Merge "update.py: add --local-dist-riscv64 for updating riscv64 prebuilts." into main am: 2b03683e40 am: 979458a8e2

Original change: https://android-review.googlesource.com/c/platform/prebuilts/runtime/+/2662199

Change-Id: I92e8c34e233c9f69f607b9869da9152de83ee84c
Signed-off-by: Automerger Merge Worker <[email protected]>