tee domain is a vendor domain

As a result, Keymaster and DRM HALs are permitted to talk to tee domain
over sockets. Unfortunately, the tee domain needs to remain on the
exemptions list because drmserver, mediaserver, and surfaceflinger are
currently permitted to talk to this domain over sockets.

We need to figure out why global policy even defines a TEE domain...

Test: mmm system/sepolicy
Bug: 36601092
Bug: 36601602
Bug: 36714625
Bug: 36715266
Change-Id: I0b95e23361204bd046ae5ad22f9f953c810c1895