Include a cfg in /etc/default/grub.d/ for lubuntu-grub-theme.

debian/changelog

@@ -1,3 +1,9 @@
+lubuntu-artwork (20.10.2) groovy; urgency=medium
+
+  * Add lubuntu-grub-theme.cfg for setting GRUB_THEME variable.
+
+ -- Raman Sarda <theloudspeaker@disroot.org>  Sun, 26 Jul 2020 01:45:26 +0530
+
 lubuntu-artwork (20.10.1) groovy; urgency=medium
 
   [ Jacob Sawicki ]

debian/lubuntu-grub-theme.install

@@ -1 +1,2 @@
 usr/share/grub/themes/
+src/etc/default/grub.d/lubuntu-grub-theme.cfg /etc/default/grub.d/

src/etc/default/grub.d/lubuntu-grub-theme.cfg

@@ -0,0 +1 @@
+GRUB_THEME=/usr/share/grub/themes/lubuntu-grub-theme/theme.txt