DO NOT MERGE Wait WINDOWS_CHANGED event when a popup is shown

For leacy apps, revoking permission shows the confirmation dialog popup
before the pemission is actually revoked. This popup is detected with
not WINDOW_CONTENT_CHANGED but WINDOWS_CHANGED event.

ag/969033 caused the regression around this logic. This change makes it
not to see WINDOWS_CHANGED event but only WINODW_CONTENT_CHANGED event.

This CL changes it to see WINDOWS_CHANGED event.

Bug: 139639150
Test: Ran PermissionsHostTest#testCompatRevoked22 on eve and sargo
Change-Id: If046532a4860e10fbd0311d555a5c2914bac31f2