Merge "cargo2rulesmk.py: Support customizing rustc" into main am: a3f72f8382 am: 76ebade138 am: 13b5d1261a am: fcb180b6b5

Original change: https://android-review.googlesource.com/c/platform/development/+/2726754

Change-Id: I20d03d596b38a2c372ed9eccc08c76f8487d89cc
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>