[res] Fix OverlayManagerPerfTest

The test was implemented in a really flaky way:

- It didn't wait for the overlay disablement propagation
  correctly, making the setEnabled() tests measure the
  phase of the Moon. Now the test is more reliable, but
  unfortunately it also depends on the broadcast delivery
  timings and activity restarts and redraws, so I doubt there's
  a way to make it that much more precise.

- It installed some APKs that Play Protect doesn't see often
  and brings up a popup asking to upload them for scanning,
  and the popup default timeout is 1hr *per APK*.
  Now the timeout is 10s and the installation happens in
  parallel, making the whole wait to be about 10-20s

Test: atest OverlayManagerPerfTest
Flag: EXEMPT tests-only change
Change-Id: Iac9f85866cc0dbdc1b567ac599a92b2fd8998932