Fix alert type registration glitch.

Author: justinkambic

x-pack/plugins/uptime/public/lib/adapters/framework/new_platform_adapter.tsx

@@ -40,9 +40,12 @@ export const getKibanaFrameworkAdapter = (
     triggers_actions_ui,
   } = plugins;
 
-  alertTypeInitializers.forEach(init =>
-    triggers_actions_ui.alertTypeRegistry.register(init({ autocomplete }))
-  );
+  alertTypeInitializers.forEach(init => {
+    const alertInitializer = init({ autocomplete });
+    if (!triggers_actions_ui.alertTypeRegistry.has(alertInitializer.id)) {
+      triggers_actions_ui.alertTypeRegistry.register(init({ autocomplete }));
+    }
+  });
 
   let breadcrumbs: ChromeBreadcrumb[] = [];
   core.chrome.getBreadcrumbs$().subscribe((nextBreadcrumbs?: ChromeBreadcrumb[]) => {