Add some strings for bubbles; update permission prompt string

* Alters permission prompt text
* Updates settings button content description
* Adds content descriptions for when a single bubble or the stack of
  bubbles is focused (just adds the strings, doesn't actually do anything)
* Adds strings for moving the bubbles around on the screen; these will
  be added as actions in a11y local context menu

Bug: 123541035
Test: it compiles
Change-Id: I069e012eafc7de3b3a28866b6f73fc3227628394