Turn on always link for Crashlytics (#505)

Author: a-maurice

crashlytics/CMakeLists.txt

@@ -106,12 +106,6 @@ endif()
 
 unity_pack_cs(firebase_crashlytics_cs)
 
-# Crashlytics has a special file to prevent il2cpp from stripping symbols.
-unity_pack_file(
-  "link.xml"
-  PACK_PATH "Firebase/Plugins/Crashlytics"
-)
-
 if (FIREBASE_INCLUDE_UNITY)
   generate_dependencies_xml(Crashlytics
     IOS_DEPS

crashlytics/link.xml

@@ -14,6 +14,10 @@
  * limitations under the License.
  */
 
+// Always link the Crashlytics assembly, since it tends to be stripped,
+// and a valid use case doesn't require the user to use the class directly.
+[assembly: UnityEngine.Scripting.AlwaysLinkAssembly]
+
 namespace Firebase.Crashlytics {
   using System;
   using System.Diagnostics;

crashlytics/src/Crashlytics.cs

@@ -15,7 +15,6 @@
  */
 
 namespace Firebase.Crashlytics {
-  using System;
   using System;
   using UnityEngine;
 

crashlytics/src/Metadata.cs

@@ -67,6 +67,11 @@ Support
 
 Release Notes
 -------------
+### Upcoming
+- Changes
+    - Crashlytics (Android): Fixed an [issue](https://github.com/firebase/quickstart-unity/issues/1116)
+      with symbols being stripped when using the tgz package.
+
 ### 10.0.1
 - Changes
     - Crashlytics (Android): Fixed a critical [issue](https://github.com/firebase/firebase-android-sdk/issues/4223) 

docs/readme.md

@@ -278,20 +278,6 @@
             }
           }
         },
-        {
-          "importer": "PluginImporter",
-          "platforms": [
-            "Editor",
-            "Standalone",
-            "Android",
-            "iOS",
-            "tvOS"
-          ],
-          "cpu": "AnyCPU",
-          "paths": [
-            "Firebase/Plugins/Crashlytics/link.xml"
-          ]
-        },
         {
           "importer": "DefaultImporter",
           "paths": [

unity_packer/debug_single_export_json/crashlytics.json

@@ -433,14 +433,6 @@
             }
           }
         },
-        {
-          "importer": "PluginImporter",
-          "platforms": ["Editor", "Standalone", "Android", "iOS", "tvOS"],
-          "cpu": "AnyCPU",
-          "paths": [
-            "Firebase/Plugins/Crashlytics/link.xml"
-          ]
-        },
         {
           "importer": "DefaultImporter",
           "paths": [