chore(storage, android)!: remove EXTERNAL_STORAGE permissions for Android 10/11 compat

On Android the following paths exist in app.utils.paths but are inaccessible without special permission:
  'EXTERNAL_DIRECTORY',
  'EXTERNAL_STORAGE_DIRECTORY',
  'PICTURES_DIRECTORY',
  'MOVIES_DIRECTORY',

Please follow Google's migration guides for "Scoped Storage" to store your data in a future compatible way.
https://developer.android.com/about/versions/11/privacy/storage#scoped-storage

BREAKING CHANGE: if you need READ_EXTERNAL_STORAGE/WRITE_EXTERNAL_STORAGE permission add them in your app AndroidManifest.xml

Author: mikehardy

packages/app/lib/index.d.ts

@@ -338,6 +338,7 @@ export namespace Utils {
      * Traditionally this is an SD card, but it may also be implemented as built-in storage on a device.
      *
      * Returns null if no external storage directory found, e.g. removable media has been ejected by the user.
+     * Requires special permission granted by Play Store review team on Android, is unlikely to be a valid path.
      *
      * ```js
      * firebase.utils.FilePath.EXTERNAL_STORAGE_DIRECTORY;
@@ -349,6 +350,7 @@ export namespace Utils {
 
     /**
      * Returns an absolute path to a directory in which to place pictures that are available to the user.
+     * Requires special permission granted by Play Store review team on Android, is unlikely to be a valid path.
      *
      * ```js
      * firebase.utils.FilePath.PICTURES_DIRECTORY;
@@ -358,6 +360,7 @@ export namespace Utils {
 
     /**
      * Returns an absolute path to a directory in which to place movies that are available to the user.
+     * Requires special permission granted by Play Store review team on Android, is unlikely to be a valid path.
      *
      * ```js
      * firebase.utils.FilePath.MOVIES_DIRECTORY;

packages/storage/android/src/main/AndroidManifest.xml

@@ -4,7 +4,4 @@
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.WAKE_LOCK" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
-    <!-- TODO(salakar) Not sure if this should be part of the package manifest or leave to users app manifest code? -->
-    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
-    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 </manifest>