- added audio and motion detection again

app/src/main/java/com/example/ueberwachungssystem/MainActivity.java

                             detectorService.videoDetector.startDetection();
                         }
                     } else {
-                        detectorService.videoDetector.stopDetection();
+                        if(detectorService != null) {
+                            detectorService.videoDetector.stopDetection();
+                        }
                     }
                 }
             });
                 @Override
                 public void onClick(View v) {
                     if (toggleAudio.isChecked()) {
-
+                        if(detectorService != null) {
+                            detectorService.audioDetector.startDetection();
+                        }
                     } else {
-
+                        if(detectorService != null) {
+                            detectorService.audioDetector.stopDetection();
+                        }
                     }
                 }
             });
                 @Override
                 public void onClick(View v) {
                     if (toggleBewegung.isChecked()) {
-
+                        if(detectorService != null) {
+                            detectorService.motionDetector.startDetection();
+                        }
                     } else {
-
+                        if(detectorService != null) {
+                            detectorService.motionDetector.stopDetection();
+                        }
                     }
                 }
             });