set accessibility window title

We apply same accessibility window title to all
magnification-related windows including magnification window and
magnification mode switch.

Bug: 170790760
Bug: 170790395
Test: enable Talkback to test manually and also change the language.
     atest MagnificationModeSwitchTest
     atest WindowMagnificationControllerTest
Change-Id: I3fedc5c1ac7597005421f61c7159ddfc9a278772