App 2.40.4: the recorder's listening works on Android 9

listenToProperties looked only for registerCallback (Android 10); the
car's car library has registerListener/unregisterListener. Take either,
unsubscribe property by property, and say why when it fails.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LhzAVaUyqcw5PkGjz4mWW6

app/build.gradle

@@ -34,8 +34,8 @@ android {
         applicationId "com.stinnesbeck.nilsmg4"
         minSdk 27
         targetSdk 36
-        versionCode 148
-        versionName "2.40.3"
+        versionCode 149
+        versionName "2.40.4"
 
         // Nothing about the server ships in the APK: its URL and ingest token are entered in
         // the app's Server tab (ServerConfig), and the database is only reachable by the server.