Allow a service certificate to be specified for provisioning

[ Merge of http://go/wvgerrit/48400 ]

Client identification information has recently been enabled in
provisioning messages. For privacy concerns this information
is being encrypted with a default service certificate.
Apps need to be able to override the default one to allow
for provisioning with third party provisioning services.

Bug: 78420508
Test: WV unit, integration tests
      New WvCdmRequestLicenseTest.ProvisioningTestWithServiceCertificate test
      GTS MediaDrmTestCases

Change-Id: Iee61ad47d33ce011efbea4eb90f7e4b1f032d15f

libwvdrmengine/cdm/test/wv_cdm_metrics_test.cpp

@@ -22,6 +22,12 @@ using ::testing::Lt;
 using ::testing::Test;
 using wvcdm::CdmResponseType;
 
+namespace {
+
+const std::string kEmptyServiceCertificate;
+
+}  // unnamed namespace
+
 namespace wvcdm {
 
 // This class is used to test the metrics-related feaures of the
@@ -46,9 +52,10 @@ TEST_F(WvContentDecryptionModuleMetricsTest, EngineOnlyMetrics) {
 
   // This call will create a CdmEngine instance with an EngineMetrics instance.
   EXPECT_EQ(wvcdm::NO_ERROR,
-            decryptor_.GetProvisioningRequest(cert_type, cert_authority,
-                                              kDefaultCdmIdentifier, &request,
-                                              &provisioning_server_url));
+            decryptor_.GetProvisioningRequest(
+                cert_type, cert_authority, kDefaultCdmIdentifier,
+                kEmptyServiceCertificate, &request,
+                &provisioning_server_url));
 
   drm_metrics::WvCdmMetrics metrics;
   ASSERT_EQ(wvcdm::NO_ERROR,