Disabling events checks for successful gestures by default

Launcher tests will still perform checks upon every gesture completion.

All tests using tapl will still use events for diagnostics if the
gesture fails.

The benefit is that system health and other platform tests won't have to
use expensive logcat, and moreover, wait seconds for the events to
appear in logcat because of buffering in logcat.

Change-Id: I3b5a0965d9432144d0c4a8b40ebe2fa89b19a689