Remove the callback from the handler when the activity is destroyed

[saketkumar]

Remove the callback from the handler when the activity is destroyed, As it will cause a leak when we don't need the handler anymore.
Handler being used during double backpress to exit but not removed. It may cause crash on some devices.

@opticod Can i fix this?

[opticod]

Yes..
Do u have any memory graph screenshot showing memory leak?