Magnification button is movable by dragging the icon

1.The magnification button is movable by dragging the icon.
2.Switching magnification mode by single-tapping the icon.

Bug: 158104770
Test: atest WindowMagnificationManagerTest, atest MagnificationModeSwitchTest
Change-Id: Id0725c2a6f3fce24f1063141f203e73de6db7592
2 files changed