add Drawable Alias
Add an alias to a drawable that can be referenced remotely. This is used for CTAs (buttons) showing in the push notifications themselves. While you can directly set a drawable resource when making your notification, it is recommended that you add a set of aliases. That way, you can change the drawable file name between versions without having to think about that when pushing different versions of your applications. You can also use aliases to make the icon names more readable or useful to anybody sending notifications to your app. Note that since Android N, notifications with button will not display icons anymore.
Parameters
alias
Drawable alias. Not case sensitive
drawable ID
Drawable resource ID to use