Protect against Bluetooth share crash because of invalid timer callback

If the timer callback is not set when fired, a SIGSEGV will ensue. This
patch checks to make sure the callback is set before invoking the
function.

Bug: 17307367
Change-Id: I2ee284bdbd3b54a368e373d9ac9e6e47205dcff6
1 file changed
tree: 7e66035de1f0f0e7b428216c8050dfb640395709
  1. android/