java.lang.RuntimeException: startPreview failed
	at android.hardware.Camera.startPreview(Native Method)
	at com.google.android.gms.vision.CameraSource$zzc.onPictureTaken(Unknown Source)
	at android.hardware.Camera$EventHandler.handleMessage(Camera.java:1181)
	at android.os.Handler.dispatchMessage(Handler.java:102)
	at android.os.Looper.loop(Looper.java:163)
	at android.app.ActivityThread.main(ActivityThread.java:6238)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:933)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:823)