st/oxr: Always make actions active that have inputs

If an applications only syncs a subset of action sets, the actions from all
sets that are not synced get the active bit reset.

Once the application starts syncing the previously not synced sets again,
the actions have to become active again.

src/xrt/state_trackers/oxr/oxr_input.c

@@ -591,6 +591,8 @@ oxr_source_cache_update(struct oxr_logger *log,
 	}
 
 	if (cache->num_inputs > 0) {
+		cache->current.active = true;
+
 		/*!
 		 * @todo Combine multiple sources for a single subaction path
 		 * and convert type as required.