header-checker: Remove aosp_{arm64,x86}_ab

This commit removes aosp_arm64_ab and aosp_x86_ab.  They have been
removed from the master branch and we don't need them anymore.

See also.
https://android-review.googlesource.com/c/platform/build/+/989349/

Bug: 135977699
Test: ./utils/create_reference_dumps.py -l libmediametrics
Change-Id: I1b1bf5d95cc35d9b9bf6180890acb602b54829be
1 file changed