Add error detail metric to some session methods

[ Merge from http://go/wvgerrit/71726 ]

Adds an error detail metric attribute to RestoreUsageSession and
RestoreOfflineSession. These metrics will now report an additional
attribute providing additional error detail for debugging.

BUG: http://b/115517916

Test: CDM Unit Tests. Manually tried GPlay.

Change-Id: Ib48361ef29d33a16150473d8967e4850bc0c623d

libwvdrmengine/cdm/metrics/src/attribute_handler.cpp

@@ -88,6 +88,14 @@ void SetAttributeField<drm_metrics::Attributes::kLicenseTypeFieldNumber,
   attributes->set_license_type(license_type);
 }
 
+template <>
+void SetAttributeField<drm_metrics::Attributes::kErrorDetailFieldNumber,
+                       CdmResponseType>(
+    const CdmResponseType &error_detail,
+    drm_metrics::Attributes *attributes) {
+  attributes->set_error_detail(error_detail);
+}
+
 template <>
 void SetAttributeField<0, util::Unused>(const util::Unused &,
                                         drm_metrics::Attributes *) {