ci: add placeholder google-services.json for Android CI builds

This placeholder config allows Android CI builds to compile without
real Firebase credentials. For production builds, replace with actual
google-services.json from Firebase Console.

FCM push notifications will not work with this placeholder config.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/android/app/google-services.json

@@ -0,0 +1,29 @@
+{
+  "project_info": {
+    "project_number": "000000000000",
+    "project_id": "moltbot-ci-placeholder",
+    "storage_bucket": "moltbot-ci-placeholder.firebasestorage.app"
+  },
+  "client": [
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:000000000000:android:0000000000000000000000",
+        "android_client_info": {
+          "package_name": "bot.molt.android"
+        }
+      },
+      "oauth_client": [],
+      "api_key": [
+        {
+          "current_key": "CI_PLACEHOLDER_NOT_FOR_PRODUCTION"
+        }
+      ],
+      "services": {
+        "appinvite_service": {
+          "other_platform_oauth_client": []
+        }
+      }
+    }
+  ],
+  "configuration_version": "1"
+}