Fix incorrect PointCloudShape transparency

[jslee02]

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[codecov]

Codecov Report

Merging #1330 into master will increase coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff            @@
##           master   #1330      +/-   ##
=========================================
+ Coverage   56.89%   56.9%   +0.01%     
=========================================
  Files         366     366              
  Lines       27167   27167              
=========================================
+ Hits        15457   15460       +3     
+ Misses      11710   11707       -3

Impacted Files	Coverage Δ
dart/dynamics/Skeleton.cpp	66.12% <0%> (+0.16%)	⬆️