Update proguard troubleshooting guide (#281)

Author: rohan-devrev

fern/docs/pages/sdks/mobile/android/troubleshooting.mdx

@@ -11,3 +11,17 @@
 
 - **Issue**: Not receiving push notifications.
   **Solution**: Ensure that your app is configured to receive push notifications and that your device is registered with the DevRev SDK.
+
+## Proguard
+
+- **Issue**: Missing class `com.google.android.play.core.splitcompat.SplitCompatApplication`.
+  **Solution**: Add the following line to your `proguard-rules.pro` file: `-dontwarn com.google.android.play.core.**`.
+
+- **Issue**: Missing class issue due to transitive Flutter dependencies. 
+  **Solution**: Add the following lines to your `proguard-rules.pro` file:
+  ```bash
+  -keep class io.flutter.** { *; }
+  -keep class io.flutter.plugins.** { *; }
+  -keep class GeneratedPluginRegistrant { *; }
+  ```
+