Add tests for IME user animation request tracking in InsetsController

Adds tests to verify that `ImeTracker` is invoked when a user-controlled animation for the IME is started.

This is verified by checking for the `ImeTracker.Token` that is passed to the `InsetsController.Host` when the animation is initiated.

- `testControlWindowInsetsAnimation_ime_createsStatsToken`: Confirms that a non-null token is created when controlling the IME.
- `testControlWindowInsetsAnimation_nonIme_noStatsToken`: Confirms that a null token is used when controlling other system bars.



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Please feel free to use your domain knowledge to make changes to the generated tests to make it more valuable for your team.
Original Change: ag/31235794
Test: ATP tests passed http://go/forrest-run/L12800030017395409
Bug: 431235865
Flag: TEST_ONLY

Change-Id: Ia06424087f358f47514592cdaa8d3f6bbe99087e