Merge "Do not attempt to generate prebuilt_kernel_modules if they are not src"...

Merge "Do not attempt to generate prebuilt_kernel_modules if they are not src" into main am: 0a9d9d6a

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/3362128



Change-Id: Ia77241f860b4ba32afba00416c784530f3fce056
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>