Cherry-picked some Autofill Javadoc improvements from master.

Test: m update-api

Bug: 64125551
Bug: 63669555
Bug: 63985284

Merged-in: Iba4817f682670e9fd6d891ae221e1fa415252e99
Change-Id: I82cbb54a522b2cf1dfb11aacc9735c932aa9af90
2 files changed