Add `gki_retrofitting_tools.zip` to GSI/GKI DIST_DIR am: 680c62a5d2 am: 7833c6b9ba

Original change: https://android-review.googlesource.com/c/platform/system/tools/mkbootimg/+/1956320

Change-Id: I2527e173b4261f0eb447bb95fad78919e638d3aa