aaudio: use xruns detected in the service

The service knows when an actual xrun occurs so we pass
that value to the client.

Bug: 38512417
Test: write_sine_callback -pl -n1 -s20 -c2 -u
Change-Id: I9e5ff1edd2e9378957309280162d7cda855f5adb
diff --git a/media/libaaudio/src/client/AudioStreamInternal.cpp b/media/libaaudio/src/client/AudioStreamInternal.cpp
index 1944d5b..2c9e7ff 100644
--- a/media/libaaudio/src/client/AudioStreamInternal.cpp
+++ b/media/libaaudio/src/client/AudioStreamInternal.cpp
@@ -490,6 +490,9 @@
             doSetVolume();
             ALOGD("%s - AAUDIO_SERVICE_EVENT_VOLUME %lf", __func__, message->event.dataDouble);
             break;
+        case AAUDIO_SERVICE_EVENT_XRUN:
+            mXRunCount = static_cast<int32_t>(message->event.dataLong);
+            break;
         default:
             ALOGE("%s - Unrecognized event = %d", __func__, (int) message->event.event);
             break;