MM-20644: Add users to teams as a SchemeAdmin based on a new configuration field on GroupTeams and GroupChannels records. (#13361)

* MM-20644: Add users to teams as a SchemeAdmin based on a new configuration field on GroupTeams and GroupChannels records.

* MM-20644: Adds SchemeAdmin to mapping of the GroupSyncable struct fields.

* MM-2064: Adds test to ensure SchemeAdmin field value is mapped.

* MM-20644: Adds missing index creation for fresh DBs.

* MM-20644: Duplicates UpdateMembersRole across Team and Channel stores. Adds tests.

* MM-20644: Fixes some old method name references.

* MM-20644: Moves variable declaration; removes Println statement.

* MM-20644: Use a SQL query instead of two to update Team and Channel members.

* MM-20644: Fixes tests; updates query.

* MM-20644: Fix permission check for patching a group syncable.

* MM-20644: Fixes test for change of permissions verification in group patch API request.

* MM-20644: Fix for ORM select vs insert.

* MM-20644: Linting fixes.

* MM-20644: Fixes some tests.

* MM-20644: Skips changing the role of guests.

* MM-20644: Added syncableID filtering

app/team.go

@@ -543,6 +543,14 @@ func (a *App) joinUserToTeam(team *model.Team, user *model.User) (*model.TeamMem
 		SchemeUser:  !user.IsGuest(),
 	}
 
+	if !user.IsGuest() {
+		userShouldBeAdmin, err := a.UserIsInAdminRoleGroup(user.Id, team.Id, model.GroupSyncableTypeTeam)
+		if err != nil {
+			return nil, false, err
+		}
+		tm.SchemeAdmin = userShouldBeAdmin
+	}
+
 	if team.Email == user.Email {
 		tm.SchemeAdmin = true
 	}