Sort outputs in redex.py
Sort outputs in redex.py

Summary:
For determinism, ensure the order of files emitted into the APK is deterministic.

Keep the original space optimization. Ensure that the tree walk is deterministic by sorting both the subdirectories as well as filenames.

Reviewed By: justinjhendrick

Differential Revision: D19809867

fbshipit-source-id: 5565f6b3a1d4113e0500bf9f7d3ff8bdcfdffcdf

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