Revise a few metrics and add unit tests.

This is a merge of Widevine cl 39040.

A few of the metrics were not implemented, or implemented incorrectly in
O MR1. This cleans them up

Bug: 64001676

Test: Re-ran unit tests and added some additional tests. GPlay Movies check.

Change-Id: I1e8bcc36fecd76e72d853306075bc46d82f45161

libwvdrmengine/include/mapErrors-inl.h

@@ -499,6 +499,8 @@ static android::status_t mapCdmResponseType(wvcdm::CdmResponseType res) {
       return kLicenseRequestInvalidSublicense;
     case wvcdm::CERT_PROVISIONING_EMPTY_SERVICE_CERTIFICATE:
       return kCertProvisioningEmptyServiceCertificate;
+    case wvcdm::LOAD_SYSTEM_ID_ERROR:
+      return kLoadSystemIdError;
   }
 
   // Return here instead of as a default case so that the compiler will warn