[DOC] include a bug URL for every API

### URL

https://developer.android.com/ndk/reference

### Problem

The API reference docs should include a bug URL for every API we ship. Folks often end up here asking for API help which we're not able to provide. If each defgroup had a bug URL associated with it we'd know where to point them (and they'd hopefully find it themselves).

We should also probably require a point-of-contact for each API so we know who to CC for questions when needed.

Start by reviewing the API reference at https://developer.android.com/ndk/reference and identify how each defgroup is represented. Done means every shipped API defgroup has an associated bug URL; clarify separately whether point-of-contact information is also required, since the issue presents that as a possible follow-up.

Written by the indexing model from the issue text.