Add timeout, method to RPC Client Label

We are missing timeout and method in label definition for rpc client
this will cause message router to failed to parse messages as there are
unexpected labels sent from oslo.messaging.

This commit added timeout and method to rpc client labels to fix the
issue.

Change-Id: I9ed133543ae6846256c1ea81602ca864f3847dec

oslo_metrics/metrics/oslo_messaging.py

@@ -21,7 +21,7 @@ rpc_server_common_labels = [
 ]
 rpc_client_common_labels = [
     'call_type', 'exchange', 'topic', 'namespace', 'version',
-    'server', 'fanout', 'process'
+    'server', 'fanout', 'process', 'method', 'timeout'
 ]
 
 rpc_processing_seconds_buckets = [

oslo_metrics/tests/test_message_process.py

@@ -69,11 +69,13 @@ class TestProcessMessage(base.BaseTestCase):
     "call_type": "call",
     "exchange": "foo",
     "topic": "bar",
+    "method": "get",
     "server": "foobar",
     "namespace": "ns",
     "version": "v2",
     "process": "done",
-    "fanout": "foo"
+    "fanout": "foo",
+    "timeout": 10
   }
 }""".encode()