Resiliently check for Cordova 2.7 .abproject

Resiliently check for Cordova 2.7 .abproject

Current versions of VSE change the .abproject file by adding a superficial, empty TemplateAppName property. Ignore it.

fixes #271425
You can change the entire check to `(this.projectData && this.projectData["TemplateAppName"])` because empty strings are falsy.