Ignore testShowHideInSameFrame on T

ImeOpenCloseStressTest#testShowHideInSameFrame() is very flaky
on T. It's passing on T QPR, and rewritten in U (also passing).

This could be a real bug on Android side as the same test is passing on
T QPR. However, let's just ignore this test as T (not QPR) does not
accept general fix now.

I7a66fd84e4094be249714c2597706ee25938adbe is an unrelated change that's in T QPR to avoid merging this CL there.

Bug: 268556567
Test: m InputMethodStressTest
Change-Id: Ibcd01e0d722f5ebb846e75f72ba4e770f7030d32
Merged-In: I7a66fd84e4094be249714c2597706ee25938adbe