Fix barcode scanner preview orientation on Nexus 5x

The code that is supposed to deal with sensor orientation has a bug. The findCamera() method
never calls Camera#getCameraInfo() method for the first camera (index 0). As a result, mCameraInfo
may never be set to reflect the properties of the camera identified with mCameraId (may instead
contain info of the other camera).

app/src/main/java/org/fedorahosted/freeotp/add/ScanActivity.java

@@ -78,7 +78,7 @@ private static int findCamera(CameraInfo cameraInfo) {
         int cameraId = Camera.getNumberOfCameras() - 1;
 
         // Find a back-facing camera, otherwise use the first camera.
-        for (; cameraId > 0; cameraId--) {
+        for (; cameraId >= 0; cameraId--) {
             Camera.getCameraInfo(cameraId, cameraInfo);
             if (cameraInfo.facing == CameraInfo.CAMERA_FACING_BACK)
                 break;