Settings UI: Fix tests that were failing with Polymer 1

Fixing 2 tests that were failing with Polymer 1:
CrSettingsPeoplePageTest.All
CrSettingsPeoplePageSyncAccountControlTest.All

In Polymer 1, all parameters for an observer must have
changed from undefined, for the observer to fire.

Bug: 931434
Change-Id: I3da032ff2586a7e1f81bc431b2008f98b44e957c
Reviewed-on: https://chromium-review.googlesource.com/c/1476143
Reviewed-by: Hector Carmona <hcarmona@chromium.org>
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#633412}
2 files changed