Merge "Remove libcppbor_external from header_libs" am: 5bf460d2ba am: 175cf078b9

Original change: https://android-review.googlesource.com/c/platform/system/keymaster/+/1524420

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I79eced32d6dfb99462494f1240fdd539bd356284