Don't try to switch to a BLS config if GRUB_ENABLE_BLSCFG is already set

There's no point on executing the script if GRUB_ENABLE_BLSCFG has already
been set.

Commit taken (see below) and modified from rhel-10-branch but adopted for
rhel-8-main branch.

   298aa12e * Only execute grub2-switch-to-blscfg if GRUB_ENABLE_BLSCFG isn't set

Resolves: #RHEL-86913

Signed-off-by: Leo Sandoval <lsandova@redhat.com>

grub2.spec

@@ -7,7 +7,7 @@
 Name:		grub2
 Epoch:		1
 Version:	2.02
-Release:	165%{?dist}
+Release:	166%{?dist}
 Summary:	Bootloader with support for Linux, Multiboot and more
 Group:		System Environment/Base
 License:	GPLv3+
@@ -307,7 +307,10 @@ if [ "$1" = 1 ]; then
 fi
 
 if [ "$1" = 2 ]; then
-	/sbin/grub2-switch-to-blscfg --backup-suffix=.rpmsave &>/dev/null || :
+    if [ -f /etc/default/grub ]; then
+	! grep -q '^GRUB_ENABLE_BLSCFG=.*' /etc/default/grub && \
+	    /sbin/grub2-switch-to-blscfg --backup-suffix=.rpmsave &>/dev/null || :
+    fi
 fi
 
 %posttrans common
@@ -523,6 +526,10 @@ fi
 %endif
 
 %changelog
+* Wed Apr 23 2025 Leo Sandoval <lsandova@redhat.com> - 2.02-166
+- Don't try to switch to a BLS config if GRUB_ENABLE_BLSCFG is already set
+- Resolves: #RHEL-86913
+
 * Thu Apr 17 2025 Nicolas Frayer <nfrayer@redhat.com> - 2.02-165
 - fs/ext2: Rework of OOB read patch
 - Resolves: #RHEL-86553