[SPARK-4468][SQL] Fixes Parquet filter creation for inequality predicates with literals on the left hand side

For expressions like `10 < someVar`, we should create an `Operators.Gt` filter, but right now an `Operators.Lt` is created. This issue affects all inequality predicates with literals on the left hand side.

(This bug existed before #3317 and affects branch-1.1. #3338 was opened to backport this to branch-1.1.)

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