transcoding: check API31 as it's available

bug: 178144708
test: unit tests; atest MediaTranscodeManagerTest
Change-Id: Idee97e5596bfe599fb294e7b71b50514ac941ead
diff --git a/media/libmediatranscoding/TranscodingUidPolicy.cpp b/media/libmediatranscoding/TranscodingUidPolicy.cpp
index 0a1ffbc..f33c54c 100644
--- a/media/libmediatranscoding/TranscodingUidPolicy.cpp
+++ b/media/libmediatranscoding/TranscodingUidPolicy.cpp
@@ -21,6 +21,7 @@
 #include <android/binder_manager.h>
 #include <android/binder_process.h>
 #include <inttypes.h>
+#include <media/TranscodingDefs.h>
 #include <media/TranscodingUidPolicy.h>
 #include <utils/Log.h>