Enable FASS assertions for Pip Exit

Add a new test rule to ExitPipTest for comparing the new FASS
assertions with the old flicker testing. If the flicker tests from one category
(presubmit/postsumbit/flaky) are passing or failing, the corresponding
FASS test should have the same behaviour.

Bug: 201523242
Test: see the results in the dashboard go/wm-tests-flicker
Change-Id: I606e57d8780c0d7cb6191890b052501b7974b034
3 files changed