fix(google): patch auth library to return correct data

Author: sogehige

patches/google-auth-library#9.1.0.patch

@@ -2,6 +2,17 @@ Index: \google-auth-library\build\src\auth\oauth2client.js
 ===================================================================
 --- \google-auth-library\build\src\auth\oauth2client.js
 +++ \google-auth-library\build\src\auth\oauth2client.js
+@@ -191,9 +191,9 @@
+                 e.message = JSON.stringify(e.response.data);
+             }
+             throw e;
+         }
+-        const tokens = res.data;
++        const tokens = JSON.parse(res.data);
+         // TODO: de-duplicate this code from a few spots
+         if (res.data && res.data.expires_in) {
+             tokens.expiry_date = new Date().getTime() + res.data.expires_in * 1000;
+             delete tokens.expires_in;
 @@ -731,9 +731,9 @@
  OAuth2Client.GOOGLE_OAUTH2_AUTH_BASE_URL_ = 'https://accounts.google.com/o/oauth2/v2/auth';
  /**