arc: Merge ActionTapMouse and ActionTapKey for GIO

Merge ActionTapMouse and ActionTapKey to ActionTap so they can convert
to each other when editing the actions.

      InputElementTest*

Bug: b:188452744
Test: unit_tests TouchInjectorTest*:ArcInputOverlayManagerTest*:
Change-Id: Ic9164e82233b0999a96ed2b9f91b8a1ca2770d14
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3471314
Reviewed-by: David Jacobo <djacobo@chromium.org>
Reviewed-by: Yuichiro Hanada <yhanada@chromium.org>
Commit-Queue: Cici Ruan <cuicuiruan@google.com>
Auto-Submit: Cici Ruan <cuicuiruan@google.com>
Cr-Commit-Position: refs/heads/main@{#976342}