Better video error handling

cameraview/src/main/java/com/otaliastudios/cameraview/Camera1.java

@@ -642,8 +642,15 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
                 videoResult.videoBitRate = mVideoBitRate;
                 videoResult.audioBitRate = mAudioBitRate;
 
-                // Initialize the media recorder
-                mCamera.unlock();
+                // Unlock the camera and start recording.
+                try {
+                    mCamera.unlock();
+                } catch (Exception e) {
+                    // If this failed, we are unlikely able to record the video.
+                    // Dispatch an error.
+                    onVideoResult(null);
+                    return;
+                }
                 mVideoRecorder = new FullVideoRecorder(videoResult, Camera1.this, mCamera, mCameraId);
                 mVideoRecorder.start();
             }

cameraview/src/main/java/com/otaliastudios/cameraview/FullVideoRecorder.java

@@ -109,6 +109,7 @@ class FullVideoRecorder extends VideoRecorder {
                 mMediaRecorder.stop();
             } catch (Exception e) {
                 // This can happen if stopVideo() is called right after takeVideo(). We don't care.
+                mResult = null;
                 LOG.w("stop:", "Error while closing media recorder. Swallowing", e);
             }
             mMediaRecorder.release();