Add GetVersion API to query the client plugin version.

Includes Widevine libraries 4.5.0.8097

Change-Id: I7590d5a60f300f6686887f62ae127b86f76e6f94
related-to-bug: 6000505

proprietary/drmwvmplugin/src/WVMDrmPlugin.cpp

@@ -332,6 +332,9 @@ DrmInfo* WVMDrmPlugin::onAcquireDrmInfo(int uniqueId, const DrmInfoRequest* drmI
                     char buffer[16];
                     sprintf(buffer, "%lu", (unsigned long)drmInfoRequestStatus);
                     drmInfo->put(String8("WVDrmInfoRequestStatusKey"), String8(buffer));
+
+                    drmInfo->put(String8("WVDrmInfoRequestVersionKey"),
+                        String8(mDrmPluginImpl->GetVersion().c_str()));
                 }
                 break;
             }