Merge changes from topic "accessibility_floating_menu_ui" into sc-dev
* changes:
Remove half circle option in size selector
Update the vector drawable for accessibility button preview preference
Remove the accessibility gesture tutorial dialog in system navigation
Update the dialog content for accessibility floating menu
Add the preference controller to control accessibility button fade preference
Add the preference controller to control accessibility button preview preference
Add the preference controller to control accessibility button opacity preference
Add the preference controller to control accessibility button size preference
Add the preference controller to control accessibility button location preference
Setup basic layout and resources for the accessibility button settings page