Mark openDefaultAppListThenIsNotDefaultAppInList as @FlakyTest

It has a 1.34% flaky rate and isn't that important.

LOW_COVERAGE_REASON=Test change

Fixes: 333036689
Test: presubmit
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:21c1cfcce492df2025466db25857067e6c842ac6)
Merged-In: Id6c128b54d43ae18aa715289f1c8428c4b761fdb
Change-Id: Id6c128b54d43ae18aa715289f1c8428c4b761fdb
1 file changed