Some masking options result in IllegalStateException

Some masking options would result in IllegalStateException.

For example, in Ranger's web UI, if we create a column masking policy with the Select Masking Option of "Hash", we will encounter an IllegalStateException. To create a column masking policy that masks the column via a hash function, currently a user has to create a column masking policy with Select Masking Option of "Custom" and expression equal to "mask_hash(

)". There are similar problems for the Select Masking Options of "Partial mask: show last 4" and "Date: show only year" as well.

It would be easier for a user to just select a desired masking option described above instead of having to create a custom masking option and fill out the expression manually.