It appears that the Font Awesome plugin config is not included in the $ARR_PLUGIN_CONFIG in the PluginProvider.php to get that functionality.
I added
"font_awesome" => [ PluginProvider::KEY_CSS => 1, PluginProvider::KEY_FOLDER => PluginProvider::VALUE_THIRD_PARTY ]
to the end of the array (in the "Third party" section) and it worked.
Oh, I also had to explicitly load the plugin.
It appears that the Font Awesome plugin config is not included in the $ARR_PLUGIN_CONFIG in the PluginProvider.php to get that functionality.
I added
"font_awesome" => [ PluginProvider::KEY_CSS => 1, PluginProvider::KEY_FOLDER => PluginProvider::VALUE_THIRD_PARTY ]
to the end of the array (in the "Third party" section) and it worked. Oh, I also had to explicitly load the plugin.