[MM-16653] Migrate "User.UpdateUpdateAt" to Sync by default (#11517)

* Migrate "User.UpdateUpdateAt" to Sync by default

* Fixed errors in app/team.go that prevented successful build

* Reverted some changes in user_store test that caused errors in pipeline

* return of UpdateUpdateAt changed to model.AppError

* Ensured that UpdateUpdateAt in sqlstore/user_store.go returns int64 and *model.AppError, adjusted tests accordingly

* Generated mocks and ensured storetest/user_store.go had no errors

* Added require.Nil(t, err) to proper places in tests

* Added 'err' for second return value as opposed to _ in 4 UpdateUpdateAt() occurrences in storetest/user_store.go

app/team.go

@@ -565,8 +565,8 @@ func (a *App) JoinUserToTeam(team *model.Team, user *model.User, userRequestorId
 		})
 	}
 
-	if uua := <-a.Srv.Store.User().UpdateUpdateAt(user.Id); uua.Err != nil {
-		return uua.Err
+	if _, err := a.Srv.Store.User().UpdateUpdateAt(user.Id); err != nil {
+		return err
 	}
 
 	shouldBeAdmin := team.Email == user.Email
@@ -897,8 +897,8 @@ func (a *App) LeaveTeam(team *model.Team, user *model.User, requestorId string)
 		})
 	}
 
-	if uua := <-a.Srv.Store.User().UpdateUpdateAt(user.Id); uua.Err != nil {
-		return uua.Err
+	if _, err := a.Srv.Store.User().UpdateUpdateAt(user.Id); err != nil {
+		return err
 	}
 
 	// delete the preferences that set the last channel used in the team and other team specific preferences