Stores magnification mode settings for multi-user

Stores the settings with the current user handle when toggling the
magnification switch button. It can prevent the magnification mode
settings missmatched when AccessibilityManagerService.switchUser
is called.

Bug: 171007010
Test: atest MagnificationModeSwitchTest
Change-Id: I074b7e427fc3d6ac068be0380704beafd7f7aa0e
2 files changed