As b/186731461, so far MagnificationModePreferenceController and other
magnification preference controllers are only used in
ToggleScreenMagnificationPreferenceFragment, which is DashboardFragment.
Since DashboardFragment already updates preference state in its
onResume, so we can remove the onResume overrides in those controllers.
Besides, we can also remove the LifeCycle dependency for the controllers
since it's not used anymore.
Bug: 186731461
Flag: NA
Test: manually
atest ToggleScreenMagnificationPreferenceFragmentTest
atest MagnificationAlwaysOnPreferenceControllerTest
atest MagnificationFollowTypingPreferenceControllerTest
atest MagnificationJoystickPreferenceControllerTest
atest MagnificationModePreferenceControllerTest
Change-Id: I379a6a3a985c9d8b7a37bbb878b84cee1bd6adfb
654e43b2e8