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/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 916c4b7..5b2e265 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -86,7 +86,7 @@
         DisplayRequests displayRequests;
         LayerRequests layerRequests;
         ClientTargetProperty clientTargetProperty;
-        float clientTargetWhitePointNits;
+        float clientTargetBrightness;
     };
 
     struct HWCDisplayMode {