1. Move unnecessary public variables into local variables
2. Use %s to update locale preference summary
3. Correct the test case name of CaptionPreviewPreferenceControllerTest
Bug: 197695932
Test: make RunSettingsRoboTests ROBOTEST_FILTER=com.android.settings.accessibility
Change-Id: I58d4d590b9b6d46c27d389217f846a780d755891
Root cause: There is a bunch of different logic of preferences in CaptionMoreOptionsFragment. It’s hard to implement new features and hard to maintain and hard to be testable.
Solution: Move out different logic of CaptionMoreOptionsFragment into controllers to reduce the complexity of the relationship between preference and fragment.
Bug: 197695932
Test: make RunSettingsRoboTests ROBOTEST_FILTER=CaptionMoreOptionsFragmentTest CaptionLocalePreferenceControllerTest
Change-Id: Ifdf3e22b027328a9f8eb13d756730ca047ece047
