Move download script to platform/prebuilts/bazel/common. am: 81f73d9388 am: 5151dd62a1 am: d2cedcdea5

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

Change-Id: I8df2f862ded36647134052e2d5fb04f1af7d4b07
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>