Allow Automotive skip IME inset animation tests.

In Automotive, auxiliary inset changes can happen when IME inset
changes, so IME inset animation test cases don't apply depending on
particular configurations.

Also put null check for lastAnimation to prevent NPE causing crash on
all subsequent tests.

Bug: 192263406
Test: atest android.server.wm.WindowInsetsAnimationControllerTests
Change-Id: I6e7020abf5fb08d07919ebad474cdef470f4bbea
1 file changed