Remove almost-all android::Singleton users

Bug: 25426213
Change-Id: I88e6206e8915cce95c3a8a8a82a4bb8fbf668141
diff --git a/libs/hwui/GradientCache.cpp b/libs/hwui/GradientCache.cpp
index aa105f9..8c46450 100644
--- a/libs/hwui/GradientCache.cpp
+++ b/libs/hwui/GradientCache.cpp
@@ -21,6 +21,8 @@
 #include "GradientCache.h"
 #include "Properties.h"
 
+#include <cutils/properties.h>
+
 namespace android {
 namespace uirenderer {