adds troubleshooting entry about Sentry.init

docs/platforms/android/troubleshooting/index.mdx

@@ -4,6 +4,16 @@ description: "Troubleshoot and resolve common issues with the Android SDK."
 sidebar_order: 9000
 ---
 
+## Obfuscated stack traces, missing Android-specific context
+
+If stack traces don't get unobfuscated properly, even though <PlatformLink to="/enhance-errors/proguard/">mapping files are uploaded correctly</PlatformLink>, or if Android context information is missing from events, a possible reason is that the SDK is initialized with `Sentry.init` instead of `SentryAndroid.init`.
+
+<Alert level="warning">
+For manual initialization on Android, <PlatformLink to="/configuration/manual-init/#manual-initialization">always use `SentryAndroid.init`</PlatformLink>.
+</Alert>
+
+From SDK version `8.0.0` on, using `Sentry.init` on Android will cause a compile-time exception.
+
 ## Excluding Unwanted Resources from APK/AAB
 
 The Sentry Android SDK bundles some resources transitively from the Sentry Java SDK that are not required for Android apps. It's not possible to exclude these resources when publishing the SDK, but you can add the following snippet to your `app/build.gradle` file to reduce the final APK size by a bit: