Use test-config phase for configuring murano tempest

Since tempest removing its config due installation we need to
move our tempest config phase into test-config instead of extra
to avoid misconfigured tests on the end.

Change-Id: I2a1d6a9b266f0d3fb0ba90d5761844909668e4b7

devstack/plugin.sh

@@ -614,13 +614,14 @@ if is_service_enabled murano; then
             start_service_broker
         fi
         setup_core_library
-        configure_murano_tempest_plugin
 
         # Give Murano some time to Start
         sleep 3
 
         # Install Murano apps, if needed
         install_murano_apps
+    elif [[ "$1" == "stack" && "$2" == "test-config" ]]; then
+        configure_murano_tempest_plugin
     fi
 
     if [[ "$1" == "unstack" ]]; then