Currently, the option to add attachment directly to comment only available in "View Issue Screen" as per screenshot below :-
As for "Resolve Issue Screen" , the option is not available. The user need to add "Attachment" field to the screen and need to manually add it to the comment after upload the attachment in "Attachment" field.
Provide the option to add attachment in the comment directly as per "View Issue Screen" page.
It makes the user easier to add the attachment when resolving the issue.