Add a field indicating online vs offline licenses.

Import of http://go/wvgerrit/68188

This adds an attribute to metrics indicating if the license was online
or offline.

Also, added a unit test for CdmEngineMetricsImpl.

Test: Unit tests. GPlay manual. GTS tests.
Bug: 115523917

Change-Id: Id315c643048914a2c51904451f9665987bc87eb7

libwvdrmengine/cdm/metrics/src/attribute_handler.cpp

@@ -80,6 +80,14 @@ void SetAttributeField<drm_metrics::Attributes::kKeyRequestTypeFieldNumber,
   attributes->set_key_request_type(key_request_type);
 }
 
+template <>
+void SetAttributeField<drm_metrics::Attributes::kLicenseTypeFieldNumber,
+                       CdmLicenseType>(
+    const CdmLicenseType &license_type,
+    drm_metrics::Attributes *attributes) {
+  attributes->set_license_type(license_type);
+}
+
 template <>
 void SetAttributeField<0, util::Unused>(const util::Unused &,
                                         drm_metrics::Attributes *) {