Bug 1896215 - Add capability to target experiments based on Install R…

…eferrer response. r=android-reviewers,jlockhart,twhite

Differential Revision: https://phabricator.services.mozilla.com/D221263

mobile/android/fenix/app/src/main/java/org/mozilla/fenix/messaging/CustomAttributeProvider.kt

@@ -44,7 +44,11 @@ object CustomAttributeProvider : JexlAttributeProvider {
                 // By convention, we should use snake case.
                 "is_first_run" to isFirstRun,
                 "is_review_checker_enabled" to isReviewCheckerEnabled,
-
+                "install_referrer_response_utm_source" to settings.utmSource,
+                "install_referrer_response_utm_medium" to settings.utmMedium,
+                "install_referrer_response_utm_campaign" to settings.utmCampaign,
+                "install_referrer_response_utm_term" to settings.utmTerm,
+                "install_referrer_response_utm_content" to settings.utmContent,
                 // This camelCase attribute is a boolean value represented as a string.
                 // This is left for backwards compatibility.
                 "isFirstRun" to isFirstRun.toString(),