fix(scripts): use portable lowercase in normalize_bool for Bash 3.2

Replace ${1,,} (Bash 4+) with printf/tr to fix "bad substitution" on
macOS stock Bash 3.2, matching the existing pattern in gateway.sh.

fixes #1485

Signed-off-by: Florent Benoit <fbenoit@redhat.com>

Author: benoitf

tasks/scripts/gateway-vm.sh

@@ -58,7 +58,9 @@ normalize_arch() {
 }
 
 normalize_bool() {
-  case "${1,,}" in
+  local val
+  val="$(printf '%s' "$1" | tr '[:upper:]' '[:lower:]')"
+  case "${val}" in
     1|true|yes|on) echo "true" ;;
     0|false|no|off) echo "false" ;;
     *)

tasks/scripts/package-snap.sh

@@ -59,7 +59,9 @@ infer_snap_arch() {
 }
 
 normalize_bool() {
-	case "${1,,}" in
+	local val
+	val="$(printf '%s' "$1" | tr '[:upper:]' '[:lower:]')"
+	case "${val}" in
 	1 | true | yes | on) echo "1" ;;
 	0 | false | no | off) echo "0" ;;
 	*)