Merge changes I2618c2be,Ie8b9d8b9,I2f39f99c

* changes:
  Support GetPropertyByteArray for getting metrics.
  CDM Metrics Protocol buffer serialization.
  Refactored metrics to support pull model.

libwvdrmengine/mediadrm/src_hidl/WVDrmPlugin.cpp

@@ -714,6 +714,10 @@ Return<void> WVDrmPlugin::getPropertyByteArray(
     }
   } else if (name == "serviceCertificate") {
     value = StrToVector(mPropertySet.service_certificate());
+  } else if (name == "metrics") {
+    std::string metrics_value;
+    mCDM->GetSerializedMetrics(&metrics_value);
+    value = StrToVector(metrics_value);
   } else {
     ALOGE("App requested unknown byte array property %s", name.c_str());
     status = android::ERROR_DRM_CANNOT_HANDLE;