split platforms by comma as documented

[chonton]

@rohanKanojia - this update makes the platform elements behave as documented.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

100.0% Coverage
0.0% Duplication

[codecov]

Codecov Report

Merging #1651 (374ef8b) into master (2d535a1) will not change coverage.
The diff coverage is 100.00%.

❗ Current head 374ef8b differs from pull request most recent head 34863f9. Consider uploading reports for the commit 34863f9 to get more accurate results

@@            Coverage Diff            @@
##             master    #1651   +/-   ##
=========================================
  Coverage     63.85%   63.85%           
  Complexity     2184     2184           
=========================================
  Files           170      170           
  Lines          9947     9947           
  Branches       1363     1363           
=========================================
  Hits           6352     6352           
  Misses         3062     3062           
  Partials        533      533           

Impacted Files	Coverage Δ
...bric8/maven/docker/config/BuildXConfiguration.java	88.46% <100.00%> (ø)