Add script to fetch OpenJDK 21 prebuilts am: f849b278a3

Original change: https://android-review.googlesource.com/c/platform/prebuilts/jdk/jdk21/+/2850965

Change-Id: I1f43625dc72a93433a26cf4cafb4ca19b7dc4813
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
tree: 8bb389927994679bd1327672cfa8b9fa1f540fa3
  1. linux-x86/
  2. BUILD.bazel
  3. manifest.xml
  4. update.sh