Fixes for a11y selection

- TextView should request focus before performing selection on
  non-editable text, since selection requires focus. On the a11y
  service side, input focus should not matter when selecting
  non-editable text.
- Remove clickable and long-clickable states, since these are present
  due to TextView#setTextIsSelectable.
- Make UI controller changes consistent between SET_SiELECTION and
  SET_TEXT. Using SET_SELECTION means the action mode menu won't pop up
  and the left/right selection handles won't appear. Interactions
  between multiple EditTexts were previously inconsistent

- Delete some obsolete javadoc

Bug: 218357385
Test: builds and install: highlighting is consistent between SET
actions. highlighting works when selecting text in TalkBack, without
the service needing to purposely put input focus,
atest AccessibilityTextTraverssalText

Change-Id: I67986020aa112d45bd670f77b2b415617226c094