Add tensorflow and other dependencies
Add tensorflow and other dependencies

- Tensorflow v2.3.1
- Flatbuffers v1.12.0
- gemmlowp (@ Tensorflow's commit)
- ruy (@ Tensorflow's commit)

GitOrigin-RevId: d17cbf1c87926b7823b3b57740245da3da585a30

google-coral/coralmicro,google-coral/coralmicro,google-coral/coralmicro,google-coral/coralmicro,google-coral/coralmicro