Use umbrella instead of a direct include in timing module (#58540)

Summary:

Changelog: [Internal]

Update the timing module to use `React/Debug.h` umbrella include instead of a direct one.

Differential Revision: D120137164

Author: j-piasecki

packages/react-native/ReactCommon/react/timing/primitives.h

@@ -9,7 +9,7 @@
 
 #include <react/cxxstableapi/UmbrellaGuard.h>
 
-#include <react/debug/flags.h>
+#include <React/Debug.h>
 #include <chrono>
 #include <cmath>
 #include <functional>