cargo2ebuild: Use "metapackage" as the LICENSE for empty crates.

Empty crates are only placeholders of generated code so use the
metapackage placeholder license.

BUG=None
TEST=Run cargo2ebuild.py

Change-Id: I4737be89872e922be885a27b9431975a93aea745
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/3774524
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Auto-Submit: Allen Webb <allenwebb@google.com>
Tested-by: Allen Webb <allenwebb@google.com>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>
1 file changed