Finish certain activities when using Escape

Some activities are styled to look and behave like dialogs while
not being one. Our intention is to have Escape close dialogs, and
this change will apply the same logic to activities that use
`closeOnTouchOutside`.

Bug: 281809692
Test: Use voice input in Google Play search; confirmed that Escape
will close the activity that looks like a dialog

Change-Id: I2e3c75e44de750b248e8c78071fcf639bd78a152