[PUSH-23646][bugfix] use add() method for cdvPluginPostBuildExtras variable instead of overriding it
[PUSH-23646][bugfix] use add() method for cdvPluginPostBuildExtras variable instead of overriding it

Pushwoosh/pushwoosh-phonegap-3.0-plugin,Pushwoosh/pushwoosh-phonegap-3.0-plugin,Pushwoosh/pushwoosh-phonegap-3.0-plugin,Pushwoosh/pushwoosh-phonegap-3.0-plugin