This change fixes two javascript errors:
1. TypeError: Cannot read property 'name' of undefined. This existed
when a project without global capabilities was loaded after one with
global capabilities. Inside of the section dom-repeat, the old
section id was being used to compute the permission name. This is
fixed by resetting sections to an empty array before setting the
new value returned by the api.
2. TypeError: Cannot read property 'values' of undefined. This existed
when _computeLabel was called with a label is not included in the
list of 'labels' returned by the api. In this case, label values
should not be rendered, the permission still exists, and acts like a
non-label permission
Bug: Issue 7497
Change-Id: Ib7451f2bae5d2349289f41070a305bf086017c65
(cherry picked from commit 4d039c8db2)
57df22313d