docs: Update ArrayAdapter JavaDoc comments

update the introduction to:

- streamline wording by focusing on practical uses in introduction
- include crosslinks to relevant guides & examples
- a note about RecyclerView given it is mentioned in this context
- favor a p element with a note class applied
- incorporate reword via joe’s input on connecting topics

Test: Docs change only. Tested with doc build run.
Change-Id: I66511db5a978bff4e46d3d6080b00c2b7e6dfa64