Merge Missed calls onto tiles by Contact Uri

Doesn't migrate pre-existing users since only in droidfood and won't
break the current experience (just add additional functionality).

Test: PeopleSpaceUtilsTest, PeopleSpaceWidgetManagerTest
Bug: 163617224
Change-Id: If2ac7a09e4e8efa18c816f1382e3df5235c4b656