Add system to avoid a crash stopping tests from running

Add a system such that when a crash happens on the main thread, it is
delayed until the tests complete, then thrown.

Also mark some old flaky tests as not flaky as they should be good
now.

Test: runtest systemui
Change-Id: Ic18a38daf4a93dab63549d834fa00f295644fbf1
Fixes: 62935720, 62251903, 62529569