Location id fix

should fix http://manage.dimagi.com/default.asp?146818 and http://manage.dimagi.com/default.asp?147063

fixes a subtle but bad bug introduced in https://github.com/dimagi/commcare-hq/commit/ee7cad2d338c72a99906b3ba60734b5cd794e839

once location_id was a first class property it was no longer returned in `dynamic_properties` calls which
prevented it from being returned in API results and OTA restores, breaking a lot of application flows that 
depended on this value.

we may need to write a migration for intrahealth to fix their old forms.