Upgrade Angular from 1.5 => 1.8
I'm not sure why CiviCRM core still ships with angular 1.5.
The latest in the 1.x branch is 1.8.
Looking over the list of breaking changes between 1.5 and 1.8, it seems pretty minimal:
According to their website, http://blog.angularjs.org/2016/12/angular-160-released.html
While there are a number of breaking changes between 1.5 and 1.6, many only affect very rare corner cases.