update progress bar with Firebase uploading

Change the grouping of terms in your calculation of progress to force conversion to float. As your code is now, you are dividing two longs. The result of the division will be 0 until getBytesTransferred() == getTotalByteCount(), then it will be 1.

 double progress = (100.0 * taskSnapshot.getBytesTransferred()) / taskSnapshot.getTotalByteCount();