t_frc_odp_330442040
certify_bootimg: makes gki-info.txt optional am: 79627361ad am: 6236378e71 am: 8b855eb5f8

Original change: https://android-review.googlesource.com/c/platform/system/tools/mkbootimg/+/2051402

Change-Id: Ifd9e1b1c730b430314a181f2e323d2133ff23c99
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>