function configure(configureFn) {
  if (moduleManager) {
    configureFn(moduleManager);
  } else {
    configureFunctions.push(configureFn);
  }
}
Applys a configuration function on moduleManager if it exists. Otherwise
store the configuration function inside of configureFunctions list so
that they can be applied when moduleManager is instantiated.
@param {function(!AbstractModuleManager)} configureFn