Impove scrolling and drag accessibility documentation

- Specify that scroll actions should send TYPE_VIEW_SCROLLED events
- Add examples of adding and implementing the actions
- Recommend adding the scroll direction or page direction actions
- Specify more properies that should be popualted for scroll events
- Add more details on expected implementation for drag actions

Bug: 283458590
Test: n/a
Change-Id: I3dc8bbfb52fd243ba707d5b2a40732261ce906e5