Really don't output VCs with no ALT if * gets dropped

[ldgauthier]

Fix botched squash, clarify test asserts

Fixes #5650

[codecov-io]

Codecov Report

Merging #5844 into master will increase coverage by <.01%.
The diff coverage is 33.33%.

@@             Coverage Diff              @@
##             master    #5844      +/-   ##
============================================
+ Coverage     87.05%   87.05%   +<.01%     
  Complexity    32157    32157              
============================================
  Files          1978     1978              
  Lines        147433   147433              
  Branches      16206    16206              
============================================
+ Hits         128350   128351       +1     
+ Misses        13171    13168       -3     
- Partials       5912     5914       +2

Impacted Files	Coverage Δ	Complexity Δ
...ls/walkers/genotyper/GenotypingEngineUnitTest.java	93.4% <0%> (ø)	11 <0> (ø)	⬇️
...nder/tools/walkers/genotyper/GenotypingEngine.java	70.24% <100%> (ø)	73 <0> (+1)	⬆️
...titute/hellbender/tools/walkers/GenotypeGVCFs.java	90.71% <0%> (-0.43%)	100% <0%> (-1%)
...lbender/utils/variant/GATKVariantContextUtils.java	87.3% <0%> (-0.31%)	244% <0%> (-2%)
...ithwaterman/SmithWatermanIntelAlignerUnitTest.java	60% <0%> (ø)	2% <0%> (ø)	⬇️
...nder/utils/runtime/StreamingProcessController.java	67.77% <0%> (+0.47%)	33% <0%> (ø)	⬇️
...utils/smithwaterman/SmithWatermanIntelAligner.java	80% <0%> (+30%)	3% <0%> (+2%)	⬆️

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