Split ActionRow view into internface and implementation

ActionRow widget is split into an interface, ActionRow, an
implementation, ChooserActionRow. The view is continue to be
referenced by the interface everywhere in the codae.

Bug: 262278109
Test: manual testing for basic functionality
Test: atest IntentResolverUnitTests
Change-Id: Idadaaf80ea62f655719b40b10b9d23188c0e590d
3 files changed