This PR updates the gradle build file for the android_embedding_bundle
cipd package to fetch license information about the dependencies listed
under `tools/androidx/files.json`. The README file for the
android_embedding_bundle now explains how to fetch the license
information and make sure it's correct in the cipd package.
This PR also pulls a new version of android_embedding_dependencies that
includes a `LICENSE` file.
It turns out that Flutter does not re-ship anything from the embedding
bundle to Flutter end-users. These dependencies are only used to create
a classpath against which we build the Android embedder and in-tree
tests. I've updated docs/comments to clarify that since I was initially
confused about how these were used.
I'm not adding a test that compares the license info fetched from maven
against a checked-in golden, yet. Still thinking about the most
effective way to do that in combination with the steps in the README.
Migrates all `#!/usr/bin/env python` hashbang lines to use python3.
Also updates the licence tool to treat python3 scripts on par with
python 2 scripts.
Issue: https://github.com/flutter/flutter/issues/83043
