Allow build triggers to be invoked by any repo admin

Fixes #1079

endpoints/api/trigger.py

@@ -21,7 +21,7 @@ from endpoints.api.build import build_status_view, trigger_view, RepositoryBuild
 from endpoints.building import start_build
 from data import model
 from auth.permissions import (UserAdminPermission, AdministerOrganizationPermission,
-                              ReadRepositoryPermission)
+                              ReadRepositoryPermission, AdministerRepositoryPermission)
 from util.names import parse_robot_username
 from util.dockerfileparse import parse_dockerfile
 
@@ -194,7 +194,7 @@ class BuildTriggerActivate(RepositoryParamResource):
           raise NotFound()
 
         # Make sure the user has administer permissions for the robot's namespace.
-        (robot_namespace, shortname) = parse_robot_username(pull_robot_name)
+        (robot_namespace, _) = parse_robot_username(pull_robot_name)
         if not AdministerOrganizationPermission(robot_namespace).can():
           raise Unauthorized()
 
@@ -480,8 +480,7 @@ class BuildTriggerFieldValues(RepositoryParamResource):
       raise NotFound()
 
     config = request.get_json() or None
-    user_permission = UserAdminPermission(trigger.connected_user.username)
-    if user_permission.can():
+    if AdministerRepositoryPermission(namespace_name, repo_name).can():
       handler = BuildTriggerHandler.get_handler(trigger, config)
       values = handler.list_field_values(field_name, limit=FIELD_VALUE_LIMIT)