Changes to DragStartHelper as requested by API Council

Extracted OnDragStartListener interface
Moved listener interfaces out of public scope
Renamed remove to detach
Renamed handleFoo methods to onFoo
Altered example code to not use || chaining
Removed input view param on getTouchPosition
Removed getShadowBuilder

Bug: 27810240
Change-Id: I278e1201a9456ebf90023c493b4ef48b50661b9f
2 files changed