Fix kickstarts patching

Ostree doesn't manage the /var filesystem. Anything
installed there during initial filesystem setup becomes
unpatchable [1]. As a result, the kickstart install dir
/var/www/pages/feed/rel-${platform_release}/kickstart
is not updated according to patch changes. /var/www/pages/feed/rel-${platform_release}/kickstart
is currently only used for PXE boot installs.
Subcloud remote installations are using the miniboot.cfg
kickstart from the load-imported ISO
(we may want to change this in some future commit).

This commit adds kickstart update support to
pxeboot-feed.service (pxeboot_feed.sh) so that
/var/www/pages/feed/rel-${platform_release}/kickstarts
is refreshed based on the kickstart dir from
/ostree (i.e., the patched changes).

[1] https://review.opendev.org/c/starlingx/ha/+/890918

Test Plan:
1. PASS: Verify Debian build and DC system install
         (virtual lab - disk and pxe installs)
2. PASS: Verify pxe install (DC remote install) with
         patched kickstart
3. PASS: Create a patch with changes to kickstart feed:
          - modify an existing kickstart
          - create a new kickstart file
          - delete an existing file
          - create a new kickstart sub-directory
          - modify centos subdir
	 verify patch apply, ensure that changes are
         correctly applied to:
         /var/www/pages/feed/rel-${platform_release}/kickstarts
4. PASS: Revert the patch from test #3 and ensure changes
         are correctly undone in the feed dir

Closes-Bug: 2034753

Change-Id: I74804bff23a74512db6a95fa514c84a1a6ea54a8
Signed-off-by: Salman Rana <salman.rana@windriver.com>

installer/pxe-network-installer/pxe-network-installer/pxeboot_feed.sh

@@ -11,6 +11,9 @@
 #
 # ... with the kernel, initrd and other images and signature files from /boot
 #
+# This utility is also used to sync the /var/www/pages/feed/rel-xx.xx/kickstart
+# directory with the kickstart directory from /ostree.
+#
 #############################################################################
 #
 # chkconfig: 2345 98 2
@@ -215,5 +218,17 @@ done
 # rsync efi.img file
 rsync_if_not_equal "${pxeboot}/efi.img" "${feed}/efi.img"
 
+# Refresh the kickstarts feed
+kickstarts_feed="${feed}/kickstart"
+kickstarts_deploy="/ostree/1""${kickstarts_feed}"
+
+if [ ! -d "${kickstarts_deploy}" ] ; then
+    ilog "Error: deploy path '${kickstarts_deploy}' does not exist"
+    exit ${RETVAL}
+fi
+
+ilog "syncing ${kickstarts_deploy} to ${kickstarts_feed}"
+rsync -a --delete "${kickstarts_deploy}/" "${kickstarts_feed}"
+
 RETVAL=0
 exit ${RETVAL}