Fix NPEs in shortcuts

Contacts with no data will have null for their display name which in
this version isn't caught.
Add null checks and use R.string.missing_name when a contact has no
display name.

Test: Manually verified no crashes on a Pixel with O-DR when :
  * adding shortcut from overflow menu in QuickContact for a contact
    with no name
  * selecting a contact with no name when creating a shortcut by
    long pressing the home screen

Bug: 62590004
Change-Id: If0c5d93a472d1d47c6657f72ae9e202c335de75c