add number constraint for samples per MotionEvent am: 5d17838ade am: 72c8ca4a01 am: 9964d83869 am: 90dc6dc825
am: 9830f11dc6

* commit '9830f11dc6b6aa4001c79147966fdb9eaa71c2f2':
  add number constraint for samples per MotionEvent