Consistently checking state change messages

Checking for events whenever Launcher sends them.
Checking for correct events (final events, not for events from
intermediate state changes).

This should simplify diagnosing of bugs involving TAPL.
This is also supposed to fix Fallback overview tests.

Bug: 143488140
Change-Id: If053ed808ec71bf2b652ab680be5bdfe9ff8cbb9
8 files changed