Enable verbose output for grub

scripts/Common/Config/GRUB/setup.sh

@@ -10,7 +10,14 @@ then
         BOOTLOADER_ID="${BOOTLOADER_ID}" \
             bash "$BASH_SOURCE";
 else
-    sed -i "s/#\(GRUB_DISABLE_OS_PROBER\)/\1/" /etc/default/grub;
+    sed -i \
+        -e "s/#\(GRUB_DISABLE_OS_PROBER\)/\1/" \
+        -e "/^GRUB_CMDLINE_LINUX_DEFAULT=/{" \
+            -e "h; s/^/#/; p;" \
+            -e "g; s/loglevel=3 quiet//" \
+        -e "}" \
+        /etc/default/grub;
+
     grub-install --target=x86_64-efi --efi-directory="$EFI_BOOT_DIR" --bootloader-id="$BOOTLOADER_ID";
     grub-mkconfig -o "$EFI_BOOT_DIR/grub/grub.cfg";
 fi;