Adding DD rum feature flag (#24879)

* Adding DD rum feature flag

* Adding flipper

Author: kylesoskin

config/features.yml

@@ -807,6 +807,10 @@ features:
     actor_type: user
     description: enables the 2024 version of form 4142 in the disability 526 submission frontend workflow
     enable_in_development: true
+  disability_526_browser_monitoring_enabled:
+    actor_type: user
+    description: enables Datadog RUM for the disability 526 submission frontend workflow
+    enable_in_development: true
   disability_526_toxic_exposure_opt_out_data_purge:
     actor_type: user
     description: enables function that removes toxic exposure data if user has opted out from toxic exposure condition on Form 526 submission