Use _get_token_resource in role assignment list

If project matches the project from access token,
we do not have to send an API request to /projects?name=...,
because the project ID is already known.
This API request may require additional permissions, so
we want to avoid it, if possible.

Change-Id: Ice1af8686bceea6b67229dcab7cf82eef821163e
Closes-Bug: #1658189

openstackclient/identity/v3/role_assignment.py

@@ -128,7 +128,8 @@ class ListRoleAssignment(command.Lister):
         if parsed_args.project:
             project = common.find_project(
                 identity_client,
-                parsed_args.project,
+                common._get_token_resource(identity_client, 'project',
+                                           parsed_args.project),
                 parsed_args.project_domain,
             )
         elif parsed_args.authproject:

releasenotes/notes/bug-1658189-d2b390ad74c96c79.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Make ``role assignment list`` callable without administrator permissions
+    if restricted to own project with ``--project`` parameter.
+    [Bug `1658189 <https://bugs.launchpad.net/python-openstackclient/+bug/1658189>`_]