predict_step fails when input has more than one EPSG

[brunosan]

We should ensure datacubes only have one EPSG. Otherwise we raise error:

  File "/home/brunosan/code/Clay/model/src/model_clay.py", line 920, in predict_step
    raise NotImplementedError(
NotImplementedError: More than 1 EPSG code detected: {32636, 32637}

Data cube created from branch doc-prep.