Fixing callbox docker image.

BUG=b:207431904
TEST=chromite/bin/build_api --input-json input.json --output-json output.json --log-level debug chromite.api.TestService/BuildTestServiceContainers

Change-Id: I1930e7a67228defb1baa3f9fdd97b9b0b82ce7fb
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/3345754
Commit-Queue: Lat Ware <latware@google.com>
Tested-by: Lat Ware <latware@google.com>
Auto-Submit: Lat Ware <latware@google.com>
Reviewed-by: Seewai Fu <seewaifu@google.com>
Commit-Queue: Seewai Fu <seewaifu@google.com>
diff --git a/src/chromiumos/test/callbox/docker/build-dockerimage.sh b/src/chromiumos/test/callbox/docker/build-dockerimage.sh
index 2edeb1e..44fb2bc 100755
--- a/src/chromiumos/test/callbox/docker/build-dockerimage.sh
+++ b/src/chromiumos/test/callbox/docker/build-dockerimage.sh
@@ -62,8 +62,6 @@
 readonly output_dir="tmp/docker/croscallbox"
 readonly full_output_dir="${chroot_path}/${sysroot_path}/${output_dir}"
 
-prep_container
-
 build_container_image                                \
     --service "cros-callbox"                         \
     --docker_file "${script_dir}/Dockerfile"         \