added code snippet for java and kotlin in android onboarding

Author: stefanosiano

docs/platforms/android/index.mdx

@@ -143,7 +143,7 @@ class MyApplication : Application() {
      SentryAndroid.init(
         this,
          { options ->
-             options.setDsn("___PUBLIC_DSN___")
+             options.dsn = "___PUBLIC_DSN___"
              // Add data like request headers, user ip address and device name, see https://docs.sentry.io/platforms/android/data-management/data-collected/ for more info
              options.isSendDefaultPii = true
              // Enable the performance API by setting a sample-rate, adjust in production env