Fix UserRepository to use the correct callback method.

Bug: 369294724
Bug: 331853529
Bug: 360838273

Test: atest UserRepositoryImplTest
Flag: EXEMPT bugfix
(cherry picked from commit 7cb99687)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:175dd00420c6727793b724ecbb9fe90e54f8b688)
Merged-In: I8b412400b89f5c62ccfc314d49dad68400cb3e5b
Change-Id: I8b412400b89f5c62ccfc314d49dad68400cb3e5b