chore: Update Firebase integration test project setup instructions. (#2395)

* Update Firebase integration test project setup instructions.

* fix: path to resource keys

* fix: add step

* fix: mirror Tech Writer review

* remove quote

* fix: pencil

* Added service account management note.

Author: jonathanedey

CONTRIBUTING.md

@@ -156,43 +156,95 @@ below covers how to run the full test suite against an actual Firebase project.
 
 #### Integration Tests with an actual Firebase project
 
-Other integration tests require an actual Firebase project. Create a new
-project in the [Firebase Console](https://console.firebase.google.com), if you
-do not already have one suitable for running the tests against. Then obtain the
-following credentials from the project:
-
-1. *Service account certificate*: This can be downloaded as a JSON file from
-   the "Settings > Service Accounts" tab of the Firebase console. Copy the
-   file into the repo so it's available at `test/resources/key.json`.
-2. *Web API key*: This is displayed in the "Settings > General" tab of the
-   console. Copy it and save to a new text file at `test/resources/apikey.txt`.
-
-Then set up your Firebase/Google Cloud project as follows:
-
-1. Enable Firestore: Go to the Firebase Console, and select "Database" from
-   the "Develop" menu. Click on the "Create database" button. You may choose
-   to set up Firestore either in the locked mode or in the test mode.
-2. Enable password auth: Select "Authentication" from the "Develop" menu in
-   Firebase Console. Select the "Sign-in method" tab, and enable the
-   "Email/Password" sign-in method, including the Email link (passwordless
-   sign-in) option.
-3. Enable the Firebase ML API: Go to the
-   [Google Developers Console](
-   https://console.developers.google.com/apis/api/firebaseml.googleapis.com/overview)
-   and make sure your project is selected. If the API is not already enabled, click Enable.
-4. Enable the IAM API: Go to the
-   [Google Cloud Console](https://console.cloud.google.com) and make
-   sure your Firebase/Google Cloud project is selected. Select "APIs & Services >
-   Dashboard" from the main menu, and click the "ENABLE APIS AND SERVICES"
-   button. Search for and enable the "Identity and Access Management (IAM)
-   API".
-5. Grant your service account the 'Firebase Authentication Admin' role. This is
-   required to ensure that exported user records contain the password hashes of
-   the user accounts:
-   1. Go to [Google Cloud Console / IAM & admin](https://console.cloud.google.com/iam-admin).
-   2. Find your service account in the list, and click the 'pencil' icon to edit it's permissions.
-   3. Click 'ADD ANOTHER ROLE' and choose 'Firebase Authentication Admin'.
-   4. Click 'SAVE'.
+Integration tests are executed against a real life Firebase project. If you do not already
+have one suitable for running the tests against, you can create a new project in the
+[Firebase Console](https://console.firebase.google.com) following the setup guide below.
+If you already have a Firebase project, you'll need to obtain credentials to communicate and
+authorize access to your Firebase project:
+
+1. Service account certificate: This allows access to your Firebase project through a service account
+which is required for all integration tests. This can be downloaded as a JSON file from the 
+**Settings > Service Accounts** tab of the Firebase console when you click the
+**Generate new private key** button. Copy the file into the repo so it's available at
+`test/resources/key.json`.
+   > **Note:** Service accounts should be carefully managed and their keys should never be stored in publicly accessible source code or repositories.
+
+
+2. Web API key: This allows for Auth sign-in needed for some Authentication and Tenant Management
+integration tests. This is displayed in the **Settings > General** tab of the Firebase console
+after enabling Authentication as described in the steps below. Copy it and save to a new text
+file at `test/resources/apikey.txt`.
+
+
+Set up your Firebase project as follows:
+
+
+1. Enable Authentication:
+   1. Go to the Firebase Console, and select **Authentication** from the **Build** menu.
+   2. Click on **Get Started**.
+   3. Select **Sign-in method > Add new provider > Email/Password** then enable both the
+   **Email/Password** and **Email link (passwordless sign-in)** options.
+
+
+2. Enable Firestore:
+   1. Go to the Firebase Console, and select **Firestore Database** from the **Build** menu.
+   2. Click on the **Create database** button. You can choose to set up Firestore either in
+   the production mode or in the test mode.
+
+
+3. Enable Realtime Database:
+   1. Go to the Firebase Console, and select **Realtime Database** from the **Build** menu.
+   2. Click on the **Create Database** button. You can choose to set up the Realtime Database
+   either in the locked mode or in the test mode.
+
+   > **Note:** Integration tests are not run against the default Realtime Database reference and are
+   instead run against a database created at `https://{PROJECT_ID}.firebaseio.com`.
+   This second Realtime Database reference is created in the following steps.
+
+   3. In the **Data** tab click on the kebab menu (3 dots) and select **Create Database**.
+   4. Enter your Project ID (Found in the **General** tab in **Account Settings**) as the
+   **Realtime Database reference**. Again, you can choose to set up the Realtime Database
+   either in the locked mode or in the test mode.
+
+
+4. Enable Storage:
+   1. Go to the Firebase Console, and select **Storage** from the **Build** menu.
+   2. Click on the **Get started** button. You can choose to set up Cloud Storage
+   either in the production mode or in the test mode.
+
+
+5. Enable the Firebase ML API:
+   1. Go to the
+   [Google Cloud console | Firebase ML API](https://console.cloud.google.com/apis/api/firebaseml.googleapis.com/overview)
+   and make sure your project is selected.
+   2. If the API is not already enabled, click **Enable**.
+
+
+6. Enable the IAM API:
+   1. Go to the [Google Cloud console](https://console.cloud.google.com)
+   and make sure your Firebase project is selected.
+   2. Select **APIs & Services** from the main menu, and click the
+   **ENABLE APIS AND SERVICES** button.
+   3. Search for and enable **Identity and Access Management (IAM) API** by Google Enterprise API.
+
+
+7. Enable Tenant Management:
+   1. Go to
+   [Google Cloud console | Identity Platform](https://console.cloud.google.com/customer-identity/)
+   and if it is not already enabled, click **Enable**.
+   2. Then
+   [enable multi-tenancy](https://cloud.google.com/identity-platform/docs/multi-tenancy-quickstart#enabling_multi-tenancy)
+   for your project.
+
+
+8. Ensure your service account has the **Firebase Authentication Admin** role. This is required
+to ensure that exported user records contain the password hashes of the user accounts:
+   1. Go to [Google Cloud console | IAM & admin](https://console.cloud.google.com/iam-admin).
+   2. Find your service account in the list. If not added click the pencil icon to edit its
+   permissions.
+   3. Click **ADD ANOTHER ROLE** and choose **Firebase Authentication Admin**.
+   4. Click **SAVE**.
+
 
 Finally, to run the integration test suite: