android: fix voice recording — init g_rec, move includes, check startRecording result

- voice_recorder_init(db_path) in utun_bridge_init (was never called, g_rec stayed NULL)
- voice_recorder_deinit() in utun_bridge_destroy
- ViewModel: set _isRecording only after startRecording() succeeds

tools/chatgui-android/app/src/main/java/com/utun/chat/viewmodel/ChatViewModel.kt

@@ -195,11 +195,14 @@ class ChatViewModel : ViewModel() {
 
     fun startVoiceRecording() {
         val ch = _currentChannel.value ?: return
+        if (!audioRecorder.startRecording(ch.id)) {
+            LogManager.addLog("ERROR", "VM", "voice recording failed to start")
+            return
+        }
         _isRecording.value = true
         _isRecordingLocked.value = false
         recordingStartTimeMs = System.currentTimeMillis()
         _recordingDurationMs.value = 0
-        audioRecorder.startRecording(ch.id)
         LogManager.addLog("INFO", "VM", "voice recording started ch=${ch.id}")
     }