Disable immersive mode confirmation dialog during tests

The immersive mode confirmation dialog will become the focused window
which impacts some tests. We need to disable it during tests.

Fix: 183968148
Fix: 185871609
Test: atest WindowInsetsControllerTests
Change-Id: I3cf8b0f6f9a80a74ddc66bdcb91be44a4af4d26e
1 file changed