whenever the Talkback setting in SUW is pressed, and remove check for parent
Activity from SettingsPreferenceFragment.
Bug: 26734639
Change-Id: I5671735437844ac54ea68322838d9b6b5c81957f
Also cleans up unnecessary 0s and moves tint to the proper place in
relevant vector drawable XML files.
Preview layout is still WIP pending UX input, but I wanted to get this
CL in place so that we can test/demo the feature ASAP.
Bug: 22450672
Change-Id: Ic3f1500006c763df99fba2d1d16782b89d6fcae1