This extends WebRTC standalone license generator to support third_party
libraries that have nested sub-libraries with their own separate licenses
(i.e. android_deps).
Bug: webrtc:10114
Change-Id: I1a1d7bf770f87f417c3c970b7bb5eb90fef3129e
Reviewed-on: https://webrtc-review.googlesource.com/c/113945
Reviewed-by: Oleh Prypin <oprypin@webrtc.org>
Commit-Queue: Artem Titarenko <artit@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25972}