Add command line flag for extra bazel-built modules am: d06db5dd

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/2320576



Change-Id: I72c352247003b412abac22b611f704ccf4b167bb
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>