Add Missing Includes Netflix Pointed Out

(This is a merge of http://go/wvgerrit/66810)

Netflix discovered that several files were only compiling because of
transitive includes via the Metrics code. This patch adds the missing
headers they noted.

Bug: 118676365
Test: CE CDM Build
Change-Id: Ifbc4e5d4276d1c3fb9bbd677230cd431e34e5c76

libwvdrmengine/cdm/core/src/client_identification.cpp

@@ -4,6 +4,8 @@
 
 #include "client_identification.h"
 
+#include <sstream>
+
 #include "crypto_session.h"
 #include "license_protocol.pb.h"
 #include "log.h"