Exclude flaky annoatated tests

Folks seems to be using both androidx.test.filters.FlakyTest as well as
android.platform.test.annotations.FlakyTest to ignore flake tests. While
it's better that there is a more standardized doc for exlcusion, a
strong blocking  test mapping suite should exclude both.

Test: N/A
Bug: 259525599
Change-Id: Ie5cdce3ed3f5c5cea169a36189163ba530c66364