tempest: Use primary user token

This change uses an non-admin user for the autoscaling tests.

This should avoid future bug like
https://bugs.launchpad.net/aodh/+bug/1703824

Change-Id: Ia8b5244aee9b6fedb9f205c32fef968e12061e37

ceilometer/tests/integration/gabbi/gabbits-live/autoscaling.yaml

@@ -1,6 +1,6 @@
 defaults:
     request_headers:
-        x-auth-token: $ENVIRON['ADMIN_TOKEN']
+        x-auth-token: $ENVIRON['USER_TOKEN']
 
 tests:
     - name: list alarms none

ceilometer/tests/tempest/scenario/test_telemetry_integration.py

@@ -77,12 +77,14 @@ class TestTelemetryIntegration(manager.ScenarioTest):
             return endpoints[0]['endpoints'][0][endpoint_type]
 
     def _do_test(self, filename):
-        auth = self.os_admin.auth_provider.get_auth()
+        admin_auth = self.os_admin.auth_provider.get_auth()
+        auth = self.os_primary.auth_provider.get_auth()
         networks = self.os_primary.networks_client.list_networks(
             **{'router:external': False, 'fields': 'id'})['networks']
 
         os.environ.update({
-            "ADMIN_TOKEN": auth[0],
+            "ADMIN_TOKEN": admin_auth[0],
+            "USER_TOKEN": auth[0],
             "AODH_GRANULARITY": str(config.CONF.telemetry.alarm_granularity),
             "AODH_SERVICE_URL": self._get_endpoint(auth, "alarming_plugin"),
             "GNOCCHI_SERVICE_URL": self._get_endpoint(auth, "metric"),