Add HAL interface to replace aaudio system property.

Using the HAL interface instead of reading system property is a better
option when moving to AIDL HAL. The replaced property includes:
  - aaudio.mixer_bursts
  - aaudio.hw_burst_min_usec

Test: atest AAudioTests
Bug: 193275465
Change-Id: I9c9a04296e56ff083babcfa089fcdddc6b89ed94
diff --git a/services/oboeservice/AAudioServiceEndpointPlay.cpp b/services/oboeservice/AAudioServiceEndpointPlay.cpp
index 4e46033..f590fc8 100644
--- a/services/oboeservice/AAudioServiceEndpointPlay.cpp
+++ b/services/oboeservice/AAudioServiceEndpointPlay.cpp
@@ -21,6 +21,7 @@
 #include <assert.h>
 #include <map>
 #include <mutex>
+#include <media/AudioSystem.h>
 #include <utils/Singleton.h>
 
 #include "AAudioEndpointManager.h"
@@ -51,7 +52,7 @@
         mMixer.allocate(getStreamInternal()->getSamplesPerFrame(),
                         getStreamInternal()->getFramesPerBurst());
 
-        int32_t burstsPerBuffer = AAudioProperty_getMixerBursts();
+        int32_t burstsPerBuffer = AudioSystem::getAAudioMixerBurstCount();
         if (burstsPerBuffer == 0) {
             mLatencyTuningEnabled = true;
             burstsPerBuffer = BURSTS_PER_BUFFER_DEFAULT;