This change is for internal test.
Add a switch preference for magnification enable mode.
Bug: 146019459
Bug: 146473544
Test: make RunSettingsRoboTests ROBOTEST_FILTER=MagnificationEnablePreferenceControllerTest -j64
Change-Id: I85fdbb5b0efc106d5301d95802b8d6b7dbe8145d
Provide a setting for new Magnify area feature and joystick controller
Bug: 146019459
Bug: 146473544
Test: make RunSettingsRoboTests ROBOTEST_FILTER=MagnificationModePreferenceControllerTest
Test: make RunSettingsRoboTests ROBOTEST_FILTER=MagnificationWindowControlPreferenceControllerTest
Test: make RunSettingsRoboTests2
Change-Id: Ia32fa073c59ad304e9ef9eb530ba37dd24c2f2f6