Add ApiCheckerRule to WindowManagerHelperTest

- Modify ApiTest to work with ApiCheckerRule
- This also addresses the PlatformVersionMismatchException thrown.
- See go/api-checker-rule for more info

Test: atest WindowManagerHelperTest
Fixes: 281744530
Change-Id: I86797569a27aaaa4392f7b9ddd885a6ac0384c1a
1 file changed