Disable app switch drop behaviour

This behaviour causes InputDispatcher to drop input events, potentially
leading to incorrect input event streams inside the dispatcher.

This later causes a crash.

This behaviour is no longer needed, so we should remove it.

In the future, all of the related code should be deleted, as well.

Bug: 308531018
Test: none
Change-Id: I32dcfae512e84d3d7a3ada76b826c84269ef6075