Actually make the mascot wallpaper default

Author: flexiondotorg

usr/share/glib-2.0/schemas/30_ubuntu-mate.gschema.override

@@ -1,5 +1,5 @@
 [org.ArcticaProject.arctica-greeter]
-background='/usr/share/backgrounds/ubuntu-mate-common/Green-Wall-Logo.png'
+background='/usr/share/backgrounds/ubuntu-mate-jammy/Jammy-Jellyfish_WP_4096x2304_Green.png'
 background-color='#3C3B37'
 draw-grid=false
 draw-user-backgrounds=false

usr/share/glib-2.0/schemas/40_ubuntu-mate-live.gschema.override

@@ -5,7 +5,7 @@ run-command-1='<Mod4>1'
 command-1='ubiquity gtk_ui'
 
 [org.mate.background]
-picture-filename='/usr/share/backgrounds/ubuntu-mate-common/Green-Wall-Logo.png'
+picture-filename='/usr/share/backgrounds/ubuntu-mate-jammy/Jammy-Jellyfish_WP_4096x2304_Green.png'
 
 [org.mate.interface]
 accessibility=true