title: Exception: Unexpected error while getting the method or property getContactGroups on object ContactsApp
body: <p>I am making a gmail addon in which i am trying to get the user's contact groups (labels) using the code: </p>
  
  <p><code>var groups = ContactsApp.getContactGroups();</code></p>
  
  <p>I already have added required scope : <code>https://www.google.com/m8/feeds</code> in manifest file (appsscript.json) but it returns "Exception: Unexpected error while getting the method or property getContactGroups on object ContactsApp". This method was working fine when it was a default apps script project. I started getting this expection after linking my apps script project with Google cloud project. I am also using People API in my project. When I add <code>https://www.google.com/m8/feeds</code> in scopes on consent screen of Google cloud platform it does 
   not show up there. Instead, <code>https://www.googleapis.com/auth/contacts</code> is shown in the scopes list. It might be because I am using People api and both of these scopes are for read/write user's contacts. And My consent screen on Google cloud platform is still under verification. </p>
  
  <p>Also,I am not able to use any of the methods provived by <code>ContactsApp</code> class. I am getting the same exception when I used <code>var contact = ContactsApp.getContact("abc@gmail.com");</code></p>
  
  <p>Any help would be appreciated.</p>
  
  <p>Thanks</p>