Support exiting edit mode when performing click action on the magnifier

When the window magnifier is in Edit mode, performing click action on
magnifier window could allow users to exit edit mode in Accessibility
Service.

Bug: 274735471
Test: manually - attach video to the bug
Test: atest WindowMagnificationControllerTest
Change-Id: Ie8fce6e03fcde5c8551b2a0c448f25e8c4b6ebd6