Add missing permissions for Cuttlefish to support GSI testing

Once b/186727553 is fixed, booting GSI on cuttlefish will no longer load
cuttlefish's system_ext sepolicy. These domains are all private and
hence the permissions are being added to system/sepolicy to avoid
making them public(especially mediatranscoding that was changed from
public to private in Android S).

Test: build, boot
Change-Id: I4a78030015fff147545bb627c9e62afbd0daa9d7
3 files changed