Accomodate brightness space change for client target

Previous the hal reported a white point in nits. Since nits are being
removed from the composer interface, SurfaceFlinger converts a dimming
ratio reported by composer into a white point instead.

Bug: 217961164
Test: builds, boots
Change-Id: I9ceec3af80f503df0debe434bb454ec42694811b
Merged-In: I9ceec3af80f503df0debe434bb454ec42694811b
diff --git a/services/surfaceflinger/CompositionEngine/src/Output.cpp b/services/surfaceflinger/CompositionEngine/src/Output.cpp
index e036252..ff332eb 100644
--- a/services/surfaceflinger/CompositionEngine/src/Output.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/Output.cpp
@@ -1076,7 +1076,8 @@
             : mDisplayColorProfile->getHdrCapabilities().getDesiredMaxLuminance();
     clientCompositionDisplay.maxLuminance =
             mDisplayColorProfile->getHdrCapabilities().getDesiredMaxLuminance();
-    clientCompositionDisplay.targetLuminanceNits = outputState.clientTargetWhitePointNits;
+    clientCompositionDisplay.targetLuminanceNits =
+            outputState.clientTargetBrightness * outputState.displayBrightnessNits;
 
     // Compute the global color transform matrix.
     clientCompositionDisplay.colorTransform = outputState.colorTransformMatrix;