Fix NPE in ExternalRawContactEditorView

state.getPrimaryEntry(StructureName.CONTENT_ITEM_TYPE) is
returning null (which is possible based on the javadoc
of the method). Hence, we need to do a null check, and
display a default name string if it is null.

Bug: 5114827
Change-Id: If9dcf7f324e9c54b6723bb6d6b5d1fd78ac2efd3