Move download script to platform/prebuilts/bazel/common. am: 81f73d9388 am: 5151dd62a1

Original change: https://android-review.googlesource.com/c/platform/prebuilts/bazel/linux-x86_64/+/2143695

Change-Id: Ie959b72f907ecb37dbca1ddbc75d6d8e9a79c7a3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>