Hardcoded HTSJDK JEXL genotype filter bindings not working as expected for VariantFiltration.

[gokalpcelik]

Hi

https://gatk.broadinstitute.org/hc/en-us/community/posts/34245458141083-VariantFiltration-isAvailable-and-isNoCall-expressions-for-genotype-filtration-work-unexpectedly

Only isHom, isHet type entries work however isAvailable, isNoCall etc. are not working at all. This could well be a HTSJDK bug but I am not sure. VariantFiltration does not seem to have too much involvement with these hard coded JEXL directly but uses them from HTSJDK.

Issue is reproducible as of GATK 4.6.1.0.