Merge "Skip unknown check in bootclasspath_fragment (source version) if...

Merge "Skip unknown check in bootclasspath_fragment (source version) if prebuilt version is in use." into main am: 378c7a39

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/2822393



Change-Id: Ifb8a17a7dbf6f73bb727b2fce78b622cb09181a9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>