generate_json_dependency_graph.py: Add --single-jar option Allow running it on a .jar that is not from our build system. E.g. Used this to analyze r8.jar Change-Id: I53e3370419b89c5cbb4640989a45320ab5913d8d Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7113818 Commit-Queue: Henrique Nakashima <[email protected]> Auto-Submit: Andrew Grieve <[email protected]> Reviewed-by: Henrique Nakashima <[email protected]> Cr-Commit-Position: refs/heads/main@{#1539543} NOKEYCHECK=True GitOrigin-RevId: feddf6175a4c6729b98c287ecba563e3ecf736bf