chromeos-init-systemd: Handle missing SecureBoot EFI var

It seems that the SecureBoot EFI var does not appear in efivarfs on new
QEMU on arm64. In this case, SecureBoot is disabled.

BUG=b/192265868
TEST=local BE run
RELEASE_NOTE=None

Change-Id: I963a012c70e04bdab23d8db4935d110fc0afaa7c
Reviewed-on: https://cos-review.googlesource.com/c/cos/overlays/board-overlays/+/19131
Tested-by: Robert Kolchmeyer <rkolchmeyer@google.com>
Reviewed-by: Vaibhav Rustagi <vaibhavrustagi@google.com>
diff --git a/project-lakitu/chromeos-base/chromeos-init-systemd/chromeos-init-systemd-0.0.1-r26.ebuild b/project-lakitu/chromeos-base/chromeos-init-systemd/chromeos-init-systemd-0.0.1-r27.ebuild
similarity index 100%
rename from project-lakitu/chromeos-base/chromeos-init-systemd/chromeos-init-systemd-0.0.1-r26.ebuild
rename to project-lakitu/chromeos-base/chromeos-init-systemd/chromeos-init-systemd-0.0.1-r27.ebuild
diff --git a/project-lakitu/chromeos-base/chromeos-init-systemd/files/is-secure-boot b/project-lakitu/chromeos-base/chromeos-init-systemd/files/is-secure-boot
index 5c379ba..a41e7bd 100644
--- a/project-lakitu/chromeos-base/chromeos-init-systemd/files/is-secure-boot
+++ b/project-lakitu/chromeos-base/chromeos-init-systemd/files/is-secure-boot
@@ -15,8 +15,12 @@
   local sb_value
   efi="$(mktemp -d)"
   mount -t efivarfs none "${efi}"
-  # shellcheck disable=SC2086
-  sb_value="$(hexdump -v -e '/1 "%02X "' ${efi}/SecureBoot-*)"
+  if [[ -f "$(echo "${efi}"/SecureBoot-*)" ]]; then
+    # shellcheck disable=SC2086
+    sb_value="$(hexdump -v -e '/1 "%02X "' ${efi}/SecureBoot-*)"
+  else
+    sb_value=""
+  fi
   umount "${efi}"
   rmdir "${efi}"
   if [[ "${sb_value}" == "06 00 00 00 01 " ]]; then