[DON'T MERGE] Normalize GAIL encoder inputs

[ervteng]

Proposed change(s)

Normalize the GAIL encoder inputs using incoming trajectories; this was done in TF but not in Torch. This helps stabilize training and improves performance on Crawler with GAIL.

Types of change(s)

• [x] Bug fix
• [ ] New feature
• [ ] Code refactor
• [ ] Breaking change
• [ ] Documentation update
• [ ] Other (please describe)

Checklist

• [ ] Added tests that prove my fix is effective or that my feature works
• [ ] Updated the changelog (if applicable)
• [ ] Updated the documentation (if applicable)
• [ ] Updated the migration guide (if applicable)

Other comments

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