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