Add build option USE_LEGACY_AUDIO_POLICY to use either new
audio policy manager in local AudioPolicyManager.cpp
or the legacy AudioPolicyManagerBase.cpp via the policy HAL.
New features will be implemented only by the new audio policy manager.
Platform customiization will be by config file or new policy HAL.
AudioPolicyClientImplLegacy.cpp copied from AudioPolicyClientImpl.cpp
AudioPolicyInterfaceImplLegacy.cpp copied from AudioPolicyInterfaceImpl.cpp
New implementations of AudioPolicyInterface and AudioPolicyClient talking directly to
AudioPolicyManager.
Change-Id: I7a320883a1de13de2c9295343e996addf2f3c154
Eric Laurent
Glenn Kasten