CDK-713: Don't use DurableParquetAppender by default.

This is saying "if NON_DURABLE_PARQUET_PROP is set to false, then make a durable appender".

Ideally, I'd have a property named DURABLE_PARQUET_PROP and I would check if it was enabled, but we have previous releases that check for the NON_DURABLE_PARQUET_PROP so I needed to keep that property name but change our default behavior.