Report Widevine Version on Android

(This is a merge of http://go/wvgerrit/29282)

The Android API has long mandated that plugins respond to queries for a
version number, but we'd never hooked it up to the CDM's actual version
number until now.

Bug: 36867286
Test: libwvdrmdrmplugin_test
Test: libwvdrmdrmplugin_hidl_test
Change-Id: I952de4943f8e78b44d526bee66c54d31e9fe5ff1

libwvdrmengine/cdm/core/src/cdm_engine.cpp

@@ -654,6 +654,14 @@ CdmResponseType CdmEngine::QueryStatus(SecurityLevel security_level,
     bool is_srm_update_supported = crypto_session.IsSrmUpdateSupported();
     *query_response =
         is_srm_update_supported ? QUERY_VALUE_TRUE : QUERY_VALUE_FALSE;
+  } else if (query_token == QUERY_KEY_WVCDM_VERSION) {
+    std::string cdm_version;
+    if (!Properties::GetWVCdmVersion(&cdm_version)) {
+      LOGW("CdmEngine::QueryStatus: GetWVCdmVersion failed");
+      return UNKNOWN_ERROR;
+    }
+
+    *query_response = cdm_version;
   } else {
     LOGW("CdmEngine::QueryStatus: Unknown status requested, token = %s",
          query_token.c_str());