doc: Updates to release notes post-DP3

Fixed a mistake (duplicated known-issue) and changed the AfW section
title.

Also added a new adb-related bug in a new "Developer Tools" section.

See first comment for doc stage location.

bug: 28844418
bug: 28347842

Change-Id: I10138a66d596b8aeb5a35a9366950af9f4c7cc51