output sample names in Mutect2 pon header

[davidbenjamin]

Closes #5609.

@LeeTL1220 Could you review this?

[codecov-io]

Codecov Report

Merging #5733 into master will increase coverage by 0.003%.
The diff coverage is 100%.

@@               Coverage Diff               @@
##              master     #5733       +/-   ##
===============================================
+ Coverage     87.061%   87.064%   +0.003%     
- Complexity     31880     31884        +4     
===============================================
  Files           1940      1940               
  Lines         146804    146806        +2     
  Branches       16234     16234               
===============================================
+ Hits          127809    127815        +6     
+ Misses         13073     13070        -3     
+ Partials        5922      5921        -1

Impacted Files	Coverage Δ	Complexity Δ
...ls/walkers/mutect/CreateSomaticPanelOfNormals.java	94.03% <100%> (+0.184%)	22 <2> (+1)	⬆️
...ithwaterman/SmithWatermanIntelAlignerUnitTest.java	60% <0%> (ø)	2% <0%> (ø)	⬇️
...nder/utils/runtime/StreamingProcessController.java	67.773% <0%> (+0.474%)	33% <0%> (ø)	⬇️
...utils/smithwaterman/SmithWatermanIntelAligner.java	80% <0%> (+30%)	3% <0%> (+2%)	⬆️

[LeeTL1220]

Pretty straightforward.