Allow controlling the SDR white point

Test: this
Change-Id: I9ee059afd73ca0850e41072c068c9effe8362382
diff --git a/libs/hwui/Properties.cpp b/libs/hwui/Properties.cpp
index 446e81e..ba44d05 100644
--- a/libs/hwui/Properties.cpp
+++ b/libs/hwui/Properties.cpp
@@ -78,6 +78,7 @@
 
 int Properties::contextPriority = 0;
 int Properties::defaultRenderAhead = -1;
+float Properties::defaultSdrWhitePoint = 200.f;
 
 bool Properties::load() {
     bool prevDebugLayersUpdates = debugLayersUpdates;