set the same flags for all gradle JavaCompile tasks (#5256)
set the same flags for all gradle JavaCompile tasks (#5256)

* simplifying a few line in build.gradle and making all JavaCompile tasks apply the same compiler arguments
* previously this didn't apply to compileJavaTestUtils
broadinstitute/hellbender,magicDGS/gatk,broadinstitute/hellbender,magicDGS/gatk,magicDGS/gatk,broadinstitute/hellbender,magicDGS/gatk,magicDGS/gatk,broadinstitute/hellbender,broadinstitute/hellbender,magicDGS/gatk,broadinstitute/hellbender