Ignore InsetsAnimationSynchronicityTests for now

The performance impact of animating and taking screenshots is too much
and leads to flaky results: the lower the device performance at taking
screenshots, the higher the fail rate.

Bug: 168446060
Test: atest WindowInsetsAnimationSynchronicityTests
Change-Id: Ic9d2937f6e644d344fd230176938baef89580f6e
(cherry picked from commit 6379fd90bf024f0f062fa86e7d973a0d5ad8ac98)