Merge xenial-revert-grub into ubuntu/xenial [a=powersj] [r=patviafore,rcj]

amd64: revert all grub changes for xenial

For LP: #1901906, on other releases we ensured that grub-pc is always
installed with shim-signed. However, xenial has different behavior that
does not work the same. This reverts those changes back to what
livecd-rootfs was before any of those changes were made, keeping only
the autoremove packages work.

LP: #1901906

MP: https://code.launchpad.net/~powersj/livecd-rootfs/+git/livecd-rootfs-1/+merge/394910

debian/changelog

@@ -1,3 +1,10 @@
+livecd-rootfs (2.408.65) xenial; urgency=medium
+
+  [Joshua Powers]
+  * amd64: revert install grub changes on Xenial (LP: #1901906)
+
+ -- Joshua Powers <josh.powers@canonical.com>  Fri, 04 Dec 2020 13:29:27 -0800
+
 livecd-rootfs (2.408.64) xenial; urgency=medium
 
   [ Joshua Powers ]

live-build/auto/config

@@ -501,9 +501,9 @@ case $PROJECT in
 					add_package install grub-pc
 					;;
 				amd64)
-					add_package install grub-pc
-					add_package install shim-signed
+					add_package install grub-pc-bin
 					add_package install grub-efi-amd64-signed
+					add_package install shim-signed
 					;;
 				armhf)
 					add_package install flash-kernel u-boot-tools

live-build/ubuntu-cpc/hooks.d/base/disk-image-uefi.binary

@@ -86,7 +86,7 @@ install_grub() {
             efi_target=arm64-efi
             ;;
         amd64)
-            chroot mountpoint apt-get install -qqy grub-pc shim-signed grub-efi-amd64-signed
+            chroot mountpoint apt-get install -qqy grub-efi-amd64-signed grub-efi-amd64 shim-signed
             grub_modules="multiboot serial usb usb_keyboard"
             efi_target=x86_64-efi
             ;;