apex: skip symbol files when replaced with prebuilt am: 9551384f am: 7feafd15 am: 1dda598b

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/2539650



Change-Id: I3e52306e7497b946ad9b38d9a29ef4ed9d118611
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>