Add metrics for mobile versions snapshots (#28191)

* Add metrics for mobile versions snapshots

* Add notifications disabled and fix lint

* Address feedback

* Verify all references to JobTypeActiveUsers

* Fix typos

* Improve platform values

* Add test and MySQL support

server/public/model/job.go

@@ -40,6 +40,7 @@ const (
 	JobTypeDeleteOrphanDraftsMigration   = "delete_orphan_drafts_migration"
 	JobTypeExportUsersToCSV              = "export_users_to_csv"
 	JobTypeDeleteDmsPreferencesMigration = "delete_dms_preferences_migration"
+	JobTypeMobileSessionMetadata         = "mobile_session_metadata"
 
 	JobStatusPending         = "pending"
 	JobStatusInProgress      = "in_progress"
@@ -72,6 +73,7 @@ var AllJobTypes = [...]string{
 	JobTypeLastAccessibleFile,
 	JobTypeCleanupDesktopTokens,
 	JobTypeRefreshPostStats,
+	JobTypeMobileSessionMetadata,
 }
 
 type Job struct {