Public API to list all work profile contacts and phones from personal CP2.

This change adds a new Contacts.ENTERPRISE_CONTENT_URI and makes the
existing Phone.ENTERPRISE_CONTENT_URI public.
It also updates terminology in the java doc and resolves inconsistent
usage of the terms "work", "corp", "enterprise" and "managed".

Test: atest ManagedProfileContactsTest

Bug: 240954287
Change-Id: I07db823b4afb5955723967f868f07bac622724e2