Git commits in Moodle 3.9.15 by Dani Palou

commit 1385e3bc09cc9f1c86a7466c0425a309486ee82b
Author: Dani Palou <dani@moodle.com>
Date:   Fri, 27 May 2022 18:06:05 +0800
Tag:    v3.9.15

MDL-74864 forum: Allow specifying group in discussions generator


commit 4c52746b416e745c04469088a050b68d918dd0c0
Author: Dani Palou <dani@moodle.com>
Date:   Fri, 20 May 2022 17:16:15 +0800
Tag:    v3.9.15

MDL-74816 mod_resource: Allow specify default file name in generator