Bug 1020109 - Cell broadcast search list is not set correctly

The current code attempts to protect against empty objects incorrectly
since empty arrays are truthy in JavaScript. The result is empty objects
get passed to SettingsLock.set() which seems to break all subsequent
settings change observers.
Bug 1023911 - [Contacts] Investigate why integration test contacts_shortcuts_test.js is failing
Bug 989927 - [Contacts][Refactor] Create a library that reads the Global Contacts DataStore and provide a single contact
Merge pull request #19989 from comoyo/bug-1020109

Bug 1020109 - Cell broadcast search list is not set correctly. r=arthurcc
Merge pull request #20503 from arcturus/bug-1023911

Bug 1023911 - [Contacts] Investigate why integration test contacts_shortcuts_test.js is failing r=crdlc
Merge pull request #20423 from jmcanterafonseca/multi_contacts

Bug 989927 - [Contacts][Refactor] Create a library that reads the Global...
Bug 1024387 - [Collection App] Basic background support for Collection icons
Bug 1025844 - [Collections] Missing Default Icon and faster Background load