audiopolicy: port existing fixes to AudioPolicyManager

This is a squashed commit of the following fixes in
AudioPolicyManager. Only some parts of the fixes have been
ported as the custom audio policy has the other required
changes.

audiopolicy: support extended feature in audiopolicymanager
Change-Id: I1925339b591cd29f11a71c287a2e53c0627e9e62

audiopolicy: additional change for extended feature
Change-Id: I9bad6a294ddd7aee72f6f6a314666b892b730c8e

audiopolicy: Add voip flag to output flag list
Change-Id: Ifccb78a7b8579da0a65eb3ea7347756c664246a8

audiopolicy: fix to play 6.1 channel ALAC clips
Change-Id: I6b820776c0dc6e68a402886f0931439edab24a8b

audiopolicy: Add audio proxy device in audio policy
Change-Id: Idf3856a373eb7a05362f19d6cb117e9d4fb757ef

Conflicts:
        services/audiopolicy/common/managerdefinitions/src/TypeConverter.cpp

Change-Id: I7738d4b0ac11ee6d93bfd67e2553eae8518ff719