Change the update script to use openjdk builds for darwin am: d2b52bb4b8

Original change: https://android-review.googlesource.com/c/platform/prebuilts/jdk/jdk21/+/2882886

Change-Id: I2ce6de8a9ad1f174a2a4b91096707dd8868aef82
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>