Skip ToastTest#testAccessGravity and ToastTest#testAccessMargin because

Automotive does not support options for gravity or margin.

Bug: 141065955
Test: run cts -m CtsWidgetTestCases
              -t android.widget.cts.ToastTest

Change-Id: I67801662e7ee3f241bea2503e10f542d09341dc4
Merged-In: I67801662e7ee3f241bea2503e10f542d09341dc4