Cleanup: Block untrusted touches in InputDispatcher

This change removes the BlockUntrustedTouchesMode enum, and related
code, as block_untrusted_touches is now always enforced

Fix: 169067926
Test: atest WindowUntrustedTouchTest
Change-Id: Ie039fb06c2ee7e03d726545190e4e75f58978066
8 files changed