Improve stability of perf tests for ImePerfTests: 1. testShowImeWarm 2. testHideIme To improve the stability of the test, check IME state and if state is not as expected, ignore the iteration rather than failing all the iterations and hence the whole test. Bug: 180449596 Test: Run the test using steps in Readme.md Change-Id: Ie42cb49bd8f79af10e7fa48f0a3afb19f253476c