Allow empty TEST paramsters in distribution build workflows

[peterzhuamazon]

Description

Allow empty TEST paramsters in distribution build workflows

Issues Resolved

#4919

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[peterzhuamazon]

The output is a bit too long, will try to trim a bit later:

Verify Parameter 'BUILD_PLATFORM'
[Pipeline] echo
Parameter Entry: 'linux windows', [linux, windows]
[Pipeline] echo
Supported Entry: 'linux windows'
[Pipeline] echo
Verified 'BUILD_PLATFORM': linux windows

[Pipeline] echo
Verify Parameter 'BUILD_DISTRIBUTION'
[Pipeline] echo
Parameter Entry: 'tar rpm deb zip', [tar, rpm, deb, zip]
[Pipeline] echo
Supported Entry: 'tar rpm deb zip'
[Pipeline] echo
Verified 'BUILD_DISTRIBUTION': tar rpm deb zip

[Pipeline] echo
Verify Parameter 'TEST_PLATFORM'
[Pipeline] echo
Parameter Entry: 'linux', [linux]
[Pipeline] echo
Supported Entry: 'linux windows'
[Pipeline] echo
Verified 'TEST_PLATFORM': linux

[Pipeline] echo
Verify Parameter 'TEST_DISTRIBUTION'
[Pipeline] echo
Parameter Entry: 'tar', [tar]
[Pipeline] echo
Supported Entry: 'tar rpm deb zip'
[Pipeline] echo
Verified 'TEST_DISTRIBUTION': tar

Thanks @prudhvigodithi