@Override
      public void onClick(View view) {
        mPermissionRequestor
            .requestPermissions(BarcodeCaptureActivity.this, permissions, RC_HANDLE_CAMERA_PERM);
      }
Handles the requesting of the camera permission.  This includes showing a "Snackbar" message of
why the permission is needed then sending the request.
java/com/google/android/apps/authenticator/barcode/BarcodeCaptureActivity.java