Tapping settings button for opening/closing panel

Previously, the drag corner in window magnifier is only used for opening
the settings panel. We add the logic of closing the settings panel when
tapping on the drag corner again if the panel is opened and add the
corresponding accessibility action label for closing magnification
settings.

Bug: 280523938
Test: atest WindowMagnificationControllerTest WindowMagnificationTest MagnificationSettingsControllerTest windowMagnificationSettingsTest
Test: manually - attach videos to the bug
Change-Id: I17b7afa130a4e97eb743b7eec980e98f1718b0b4