[buildtool] security vulnerability present in jcommander-1.72 (#8221)
[buildtool] security vulnerability present in jcommander-1.72 (#8221)

### Motivation
jcommander-1.72 has a white source reported security vulnerability WS-2019-0490: https://www.whitesourcesoftware.com/vulnerability-database/WS-2019-0490
White source vulnerability description as it is.

> Inclusion of Functionality from Untrusted Control Sphere vulnerability found in jcommander before 1.75. jcommander resolving dependencies over HTTP instead of HTTPS. 

### Modifications
Upgrade org.testng to 7.3.0 in buildtools. That way it pulls in jcommander 1.78
merlimat/pulsar,merlimat/pulsar,merlimat/pulsar,yahoo/pulsar,yahoo/pulsar,massakam/pulsar,merlimat/pulsar,massakam/pulsar,yahoo/pulsar,merlimat/pulsar,merlimat/pulsar,massakam/pulsar,yahoo/pulsar,yahoo/pulsar,massakam/pulsar,massakam/pulsar,yahoo/pulsar,massakam/pulsar