Fixed cancel() not working correctly

The method handleMessage(Message msg) from mHandler variable was
not checking if the timer was cancelled, so
sendMessageDelayed(obtainMessage(MSG), delay) was keeping the
timer alive. The patch simply adds a boolean and checks if the
CountDownTimer was cancelled before calling
sendMessageDelayed(obtainMessage(MSG), delay)

bug: https://code.google.com/p/android/issues/detail?id=58668

Change-Id: Ic6bbb9d33a3616f8503db222513cc14ad2270cb8
Signed-off-by: jl1990 <jlcarrasco1990@gmail.com>