Depublishing some app layer methods (#29559)

* Depublishing some app layer methods

* Fixing errors

* Addressing PR review comment

* Using goimports formatting now

server/channels/app/channel.go

@@ -1245,7 +1245,7 @@ func (a *App) UpdateChannelMemberSchemeRoles(c request.CTX, channelID string, us
 
 	// If the migration is not completed, we also need to check the default channel_admin/channel_user roles are not present in the roles field.
 	if err = a.IsPhase2MigrationCompleted(); err != nil {
-		member.ExplicitRoles = RemoveRoles([]string{model.ChannelGuestRoleId, model.ChannelUserRoleId, model.ChannelAdminRoleId}, member.ExplicitRoles)
+		member.ExplicitRoles = removeRoles([]string{model.ChannelGuestRoleId, model.ChannelUserRoleId, model.ChannelAdminRoleId}, member.ExplicitRoles)
 	}
 
 	return a.updateChannelMember(c, member)
@@ -3585,7 +3585,7 @@ func (a *App) GetGroupMessageMembersCommonTeams(c request.CTX, channelID string)
 		Active:      true,
 	})
 
-	var userIDs = make([]string, len(users))
+	userIDs := make([]string, len(users))
 	for i := 0; i < len(users); i++ {
 		userIDs[i] = users[i].Id
 	}