Remove unecessary exported symbols from libhwui.so

Test: compiles and links
Bug: 150782769
Change-Id: Ib49c1bf914b6bfaad1fb29371115df7c9eec08d2
diff --git a/libs/hwui/utils/Blur.h b/libs/hwui/utils/Blur.h
index d6b41b8..6b822f0 100644
--- a/libs/hwui/utils/Blur.h
+++ b/libs/hwui/utils/Blur.h
@@ -26,9 +26,9 @@
 class Blur {
 public:
     // If radius > 0, return the corresponding sigma, else return 0
-    ANDROID_API static float convertRadiusToSigma(float radius);
+    static float convertRadiusToSigma(float radius);
     // If sigma > 0.5, return the corresponding radius, else return 0
-    ANDROID_API static float convertSigmaToRadius(float sigma);
+    static float convertSigmaToRadius(float sigma);
     // If the original radius was on an integer boundary then after the sigma to
     // radius conversion a small rounding error may be introduced. This function
     // accounts for that error and snaps to the appropriate integer boundary.