Add "Available since" text to all android/ headers.

Also fix a few missing/incorrect annotations.

Bug: http://b/143470841
Test: treehugger
Change-Id: I1d9ec8350df03df7d80f1cc2334eef45deec30ec
Merged-In: I1d9ec8350df03df7d80f1cc2334eef45deec30ec
21 files changed