audio policy: added audio HAL version in audio_policy.conf

Each hardware module section in audio_policy.conf indicates
the audio HAL version it implements.

Also added a template audio_policy.conf file with examples
of device and gain descriptors added for audio HAL version3.0.

Bug: 14815883.
Change-Id: Id219d121f81f687363f6c18f2d1684b2448dcdf4
diff --git a/services/audiopolicy/AudioPolicyManager.h b/services/audiopolicy/AudioPolicyManager.h
index 4327949..adf1b33 100644
--- a/services/audiopolicy/AudioPolicyManager.h
+++ b/services/audiopolicy/AudioPolicyManager.h
@@ -359,8 +359,9 @@
 
             void dump(int fd);
 
-            const char *const mName; // base name of the audio HW module (primary, a2dp ...)
-            audio_module_handle_t mHandle;
+            const char *const        mName; // base name of the audio HW module (primary, a2dp ...)
+            uint32_t                 mHalVersion; // audio HAL API version
+            audio_module_handle_t    mHandle;
             Vector < sp<IOProfile> > mOutputProfiles; // output profiles exposed by this module
             Vector < sp<IOProfile> > mInputProfiles;  // input profiles exposed by this module
             DeviceVector             mDeclaredDevices; // devices declared in audio_policy.conf