Touch cancellation handling

Cancel motion event that are accidental touches when a user is holding
the device and a touch stream is in progress.

- Process MT_TOOL_PALM and cancel touch when sent from firmware.

Bug: 117933934
Test: atest inputflinger_tests
Test: atest InputProcessTest
Change-Id: I80ba8b462572e5214dd1073ef0568886f71e21c9