IdentifiedUser: Clear starred changes before rereading from API

Starred changes are normally cached in IdentifiedUser, but an
IdentifiedUser instance is reused in the extension API across calls.
We need to not reuse cached starred changes in this path in case they
have changed, for example due to a mutation also made through the
extension API.

Change-Id: Ic6e2cda17d4eca3ef30ef19f692b1a0a1b38d0c1
3 files changed