Add AnimatorTestRule for use with platform animators

* Improves the AndroidX animator test isolation class
* Introduces a Platform animator test isolation class
* Introduces a helper which can be used by rules to defer exceptions on other threads to the end of a test.

Bug: 291645410
Test: atest SystemUITests
Change-Id: I4fc83f920ae74e3179549b09f35ab83553edc528