Add dump of hdr event history

Track & dump the HDRLayerInfo callback history to
aid debugging when HDR brightness changes aren't
happening

Bug: 234181960
Test: adb shell dumpsys surfaceflinger --hdrinfo
Change-Id: Ia8376517877d4c7844af6be4d488299554c164f5
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 5d2115c..80a5d32 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -1088,6 +1088,7 @@
     void dumpDisplayIdentificationData(std::string& result) const REQUIRES(mStateLock);
     void dumpRawDisplayIdentificationData(const DumpArgs&, std::string& result) const;
     void dumpWideColorInfo(std::string& result) const REQUIRES(mStateLock);
+    void dumpHdrInfo(std::string& result) const REQUIRES(mStateLock);
 
     LayersProto dumpDrawingStateProto(uint32_t traceFlags) const;
     void dumpOffscreenLayersProto(LayersProto& layersProto,