Remove AVB footer & chained vbmeta image from the loaded boot image

So that we can truncate the loaded image to its original image size, and
discover and carve out the end-of-partition boot signature simpler.

Bug: 211741246
Test: m vts_gki_compliance_test
Change-Id: Iba87938579128dde123c6cd9a58f0977b67d1cd7
1 file changed