Revert "Upgrade zerocopy to 0.7.5" am: 918dbbab86

Original change: https://android-review.googlesource.com/c/platform/system/tools/mkbootimg/+/2787439

Change-Id: I98fab42354fa6ba96c08b91e52eb0e2bf2a402d7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>