Fix flakiness in AccessibilityShortcutChooserActivityTest.

Use more precise waiting based on expected view changes instead of
waiting for idle sync.

Also includes a retry for the double-click action. I haven't yet
figured out why this is flaky, but at least the retry seems to address
it for now.

Bug: 277331877
Test: AccessibilityShortcutChooserActivityTest,
      using atest and go/abtd to run many iterations
Change-Id: I9ad5549947941de144e8bbdec7ebe387d4161976