SF: Add utility class for dumpsys formatting

The Dumper class automates stringifying (a minimal set of types for now)
and indenting.

Bug: 241285876
Test: dumpsys SurfaceFlinger --displays
Change-Id: I5581cd9cb4235e2c710e303b6ab634847554cc30
diff --git a/services/surfaceflinger/Scheduler/RefreshRateConfigs.h b/services/surfaceflinger/Scheduler/RefreshRateConfigs.h
index 0642fcb..8b89104 100644
--- a/services/surfaceflinger/Scheduler/RefreshRateConfigs.h
+++ b/services/surfaceflinger/Scheduler/RefreshRateConfigs.h
@@ -32,6 +32,7 @@
 #include "Scheduler/OneShotTimer.h"
 #include "Scheduler/StrongTyping.h"
 #include "ThreadContext.h"
+#include "Utils/Dumper.h"
 
 namespace android::scheduler {
 
@@ -336,7 +337,7 @@
         mIdleTimer->reset();
     }
 
-    void dump(std::string& result) const EXCLUDES(mLock);
+    void dump(utils::Dumper&) const EXCLUDES(mLock);
 
     std::chrono::milliseconds getIdleTimerTimeout();