Initial commit of certify_bootimg.py am: 34ac1ae663 am: 978356aa92 am: 0d616cbbd1

Original change: https://android-review.googlesource.com/c/platform/system/tools/mkbootimg/+/2002150

Change-Id: I67bc0b60835c94ffaf3c82e4e18da026b7e88812