Generic Test profile on debuggable builds

We introduce a new profile type for testing purposes.
It can be used for testing non-managed profiles, which
currently only have partial support.
It is only available on debuggable (userdebug/eng).

Bug: 170249807
Test: manual (adb shell pm create-user --user-type android.os.usertype.profile.TEST Name)
Change-Id: I37f593bbcaa9059f3afdc8668c2065bc623aa125