gform_display_disable_css_setting indicates if the Output Default CSS setting should be displayed or not.
add_filter( 'gform_display_disable_css_setting', 'your_function_name' );
Indicates if the Output Default CSS setting is shown at Forms → Settings. Default is false.
Show the Setting
This example would show the Output Default CSS setting.
add_filter( 'gform_display_disable_css_setting', '__return_true' );
This code can be used in the functions.php file of the active theme, a custom functions plugin, a custom add-on, or with a code snippets plugin.
See also the PHP section in this article: Where Do I Put This Code?
This filter was added in Gravity Forms v2.8.
This filter is located in settings.php.