support both for now

Author: ceorourke

src/sentry/mail/actions.py

@@ -47,9 +47,9 @@ def after(
             "group_id": group.id,
             "notification_uuid": notification_uuid,
         }
-
-        target_type = ActionTargetType(self.data["target_type"])
-        target_identifier = self.data.get("target_identifier", None)
+        target_type_value = self.data.get("target_type") or self.data.get("targetType")
+        target_type = ActionTargetType(target_type_value)
+        target_identifier = self.data.get("target_identifier") or self.data.get("targetIdentifier")
         skip_digests = self.data.get("skipDigests", False)
 
         fallthrough_choice = self.data.get("fallthrough_type", None)