404 error for CACHE_OFFLINE_IMAGE if module is installed using Drupal UI

The CACHE_OFFLINE_IMAGE expect that the module is installed under the "modules/contrib" directory which is not always true as if the user use the install new module form in Drupal UI, the pwa module is put in "modules/" directory only thus making the request to the offline image returns 404

saving the module path in drupalSettings and retrieving it may solve this issue.

$build['#attached']['drupalSettings']['mymodule']['mylib']['path'] = drupal_get_path('module', 'mymodule');