[CodeHealth] Migrate multiple python unit tests to Python3 Bug: 1223892 Change-Id: I72d8a2acbd7d47eb85a1fdcf461b374f79eea342 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3065476 Reviewed-by: Dirk Pranke <[email protected]> Commit-Queue: Victor Vianna <[email protected]> Cr-Commit-Position: refs/heads/main@{#917178} NOKEYCHECK=True GitOrigin-RevId: 02442ef0cb33cdbf2c38a70f2ea10263c5f81204