Optimization: Restrict signing to ACTION_UP and ACTION_DOWN while doing a motion gesture such as scrolling apps

Savings. ~2.5% of total system_server time while scrolling on apps drawer screen.

Baseline:
https://pprof.corp.google.com/?id=732307aa60aa82bf478b0c3f0e6de6be&ignore=sendMessage
https://screenshot.googleplex.com/JpWt25tXRJO

Optimized:
https://pprof.corp.google.com/?id=5040d255411f407662a7f2da0109ca48&ignore=sendMessage
https://screenshot.googleplex.com/x81k7vUUKdd

Test: atest inputflinger_tests

Change-Id: I52dd33f8203fe62bfcbde7be5a1ac45c46064585
3 files changed