docs: public GVRAndroidResource addResource(GVRAndroidResource resource)
      {
          String fileName = resource.getResourcePath();
          GVRAndroidResource resourceValue = resourceMap.get(fileName);
          if (resourceValue != null)
          {
              return resourceValue;
          }
          // Only put the resourceKey into the map for the first time, later put
          // will simply return the first resource
          resourceValue = resourceMap.putIfAbsent(fileName, resource);
          return resourceValue == null ? resource : resourceValue;
      }