Added state to CertificateProvisioning.

[ Cherry-pick of v19 http://go/wvgerrit/219310 ]
[ Merge of http://go/wvgerrit/219453 ]

To enable the CDM to determine between OEM vs DRM responses,
a state variable was needed in CertificateProvisioning.
Previously, the presence/absence of the OEM certificate in the
file system was used; however, if two apps (or single app with
multiple origins) attempts provisioning simultaneously, the
later response would trigger unexpected failures.

The main functional changes this provides is that a more informative
error will be returned to the app if they provide a provisioning
response without ever creating a provisioning request; and that
if multiple clients attempted first-stage provisioning simultaneously,
fewer errors will occur.

Bug: 391469176
Test: run_prov40_tests
Change-Id: I51a118ce73aa809bad6ecee640139a92d8518575

libwvdrmengine/cdm/core/test/certificate_provisioning_unittest.cpp

@@ -413,6 +413,9 @@ TEST_P(CertificateProvisioningTest, ProvisioningRequestFailsEmptySignature) {
 TEST_P(CertificateProvisioningTest,
        ProvisioningResponseFailsWithEmptyResponse) {
   certificate_provisioning_->Init("");
+  // Must set state if not generating request.
+  certificate_provisioning_->SetStateForTesting(
+      CertificateProvisioning::kDrmRequestSent);
 
   MockFileSystem file_system;
   std::string certificate;
@@ -425,6 +428,9 @@ TEST_P(CertificateProvisioningTest,
 TEST_P(CertificateProvisioningTest,
        ProvisioningResponseFailsIfDeviceIsRevoked) {
   certificate_provisioning_->Init("");
+  // Must set state if not generating request.
+  certificate_provisioning_->SetStateForTesting(
+      CertificateProvisioning::kDrmRequestSent);
 
   MockFileSystem file_system;
   std::string response_certificate;
@@ -445,6 +451,10 @@ TEST_P(CertificateProvisioningTest,
 
 TEST_P(CertificateProvisioningTest, ProvisioningResponseSuccess) {
   certificate_provisioning_->Init("");
+  // Must set state if not generating request.
+  certificate_provisioning_->SetStateForTesting(
+      CertificateProvisioning::kDrmRequestSent);
+
   std::string expected_certificate;
   std::string response;
   ASSERT_TRUE(MakeSignedDrmCertificate(kFakePublicKey, kSerialNumber, kSystemId,