Update ThemeEnforcement to read this new attribute, and check for Material theme.
Change the ThemeEnforcement API to replace Context#obtainStyledAttributes().
See followup CL for how this attribute is used.
PiperOrigin-RevId: 184074635
New singleSelection attribute to control whether the ChipGroup has a multiple-exclusion scope for its chips.
When set to true, the ChipGroup acts as a RadioGroup.
ChipGroup can be used purely for layout purposes when singleSelection is set to false.
PiperOrigin-RevId: 178466966