Bug 1061440 - Provide an option for restoring only apn items instead of the entire apn settings

Conflicts:
	apps/settings/js/modules/apn/apn_settings_manager.js
Merge pull request #24032 from crh0716/1061440

Bug 1061440 - Provide an option for restoring only apn items instead of the entire apn settings r=eragonj