fix: Refactor User Lifecycle Event and Report metrics logging

Improvements described in [this doc](https://docs.google.com/document/d/1X_f-kdVNnptKJnF9e5KO4WzbWqLNucJxPcnutk7cCgM/edit?resourcekey=0-LdjBpCMjyUxilDQlnyh6kg#)

Bug: 265927093
Test: atest UserJourneyLoggerTest
Change-Id: Id2632415b66834fe99fb627f9c9ed35d12ba207d
Merged-In: Id2632415b66834fe99fb627f9c9ed35d12ba207d
Merged-In: I102ed93f5a88a065f259b5cbaea42cc01c4a9ca1