Add DefaultImeVisibilityTest to test the visibility of the system default IME.

Reset IME to system default IME (adb shell ime reset) and test the show/hide behavoir of it for compatibility in both portrait and landscape mode.

Bug: 275666243
Bug: 242838873
Test: atest com.android.inputmethod.stresstest.DefaultImeVisibilityTest
Change-Id: I3da5d11e30edd75b3e8f52968158b658abe7fbf5
(cherry picked from commit 75551432)
Merged-In: I3da5d11e30edd75b3e8f52968158b658abe7fbf5