Revert "Merge remote-tracking branch 'upstream/master' into bubble-tea"

This reverts commit 2305c9f8924bbb162600d97da36d2c047ee61210, reversing
changes made to 20954fbbe8e6b3761d9e55caf485220399fbf202.
Bug 979212 - Require MockHomescreenLauncher in unit test of EdgeSwipeDetector