Android: wire Firebase google-services.json into the build (client half)

Commit the client Firebase config (bizgaze-connect, package com.bizgaze.connect)
and have the Codemagic Android step copy it into android/app/ so the google-services
Gradle plugin applies and FirebaseApp initializes — fixing the root cause of the
"Default FirebaseApp is not initialized" crash. google-services.json is client-side
(ships in the APK), safe for this private repo. The service-account key stays OUT of
git (.gitignore: *firebase-adminsdk*.json / *service-account*.json) — it goes on the
server as FCM_SERVICE_ACCOUNT separately.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

mobile/FirebaseAccount_Google/google-services.json

@@ -0,0 +1,29 @@
+{
+  "project_info": {
+    "project_number": "860472998800",
+    "project_id": "bizgaze-connect",
+    "storage_bucket": "bizgaze-connect.firebasestorage.app"
+  },
+  "client": [
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:860472998800:android:107cc0fc6936d6898dd115",
+        "android_client_info": {
+          "package_name": "com.bizgaze.connect"
+        }
+      },
+      "oauth_client": [],
+      "api_key": [
+        {
+          "current_key": "AIzaSyB6gSqIDYr21GKYA4c1e7plUBQMXIcX1Dw"
+        }
+      ],
+      "services": {
+        "appinvite_service": {
+          "other_platform_oauth_client": []
+        }
+      }
+    }
+  ],
+  "configuration_version": "1"
+}