[PM-22573] Don't call server on existing subscription (#15154)

* Don't put subscription to our server when it's existing

* Only update server when subscription-user associations change

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Co-authored-by: Matt Gibson <mgibson@bitwarden.com>

apps/browser/src/background/main.background.ts

@@ -1087,6 +1087,7 @@ export default class MainBackground {
           this.configService,
           new WebPushNotificationsApiService(this.apiService, this.appIdService),
           registration,
+          this.stateProvider,
         );
       } else {
         this.webPushConnectionService = new UnsupportedWebPushConnectionService();