flax

03d2b983 - Copybara import of the project:

Copybara import of the project: -- e40b80f94502638935d4a666a2a92a5600621e05 by Andreas Steiner <andstein@google.com>: Stores logging output in workdir. -- 290369e4a496b0e13dd32bb15291bdb873f4776e by Andreas Steiner <andstein@google.com>: Import absl.logging in ppo_main. PiperOrigin-RevId: 362886322