- Add RTT setting in Accessibility screen. - Create a controller for RTT setting preference. - Create an array strings to define the subtext. Test: Rebuild, and visual Change-Id: I248654c822284473b8a8265de4a3938af89cdf7a Merged-In: I248654c822284473b8a8265de4a3938af89cdf7a Fix: 146540478