Remove prebuilts for Rust 1.70.0 am: 2b5ca928d3

Original change: https://android-review.googlesource.com/c/platform/prebuilts/rust/+/2812802

Change-Id: I9811874c4331b7b9f834bf9f80b3e57eb9fbb7d9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>