Remove unnecessary invocations of UserDataRepository#getOrCreate()

Historically we have called

  UserDataRepository#getOrCreate()

immediately after a user becomes available. However such invocations
are redundant and not necessary as the method name implies. Let's
remove them in favor of simplicity.

There must be no user observable behavior change in this CL.

Bug: 343601565
Test: presubmit
Flag: EXEMPT refactor
Change-Id: I6a5a528bec84c5eb4e1756f9f58106951c0f841b