Making Program*.Builder classes' setters return 'this'

This is for better correspondence with the Builder pattern.
See also: Effective Java, 2nd edition.

Change-Id: Iecccd42be49dea2ed8e4b8cc38ce96379cf3c11c
diff --git a/graphics/java/android/renderscript/ProgramRaster.java b/graphics/java/android/renderscript/ProgramRaster.java
index c3ab481..55e6586 100644
--- a/graphics/java/android/renderscript/ProgramRaster.java
+++ b/graphics/java/android/renderscript/ProgramRaster.java
@@ -89,16 +89,19 @@
             mPointSprite = false;
         }
 
-        public void setPointSpriteEnable(boolean enable) {
+        public Builder setPointSpriteEnable(boolean enable) {
             mPointSprite = enable;
+            return this;
         }
 
-        public void setPointSmoothEnable(boolean enable) {
+        public Builder setPointSmoothEnable(boolean enable) {
             mPointSmooth = enable;
+            return this;
         }
 
-        public void setLineSmoothEnable(boolean enable) {
+        public Builder setLineSmoothEnable(boolean enable) {
             mLineSmooth = enable;
+            return this;
         }
 
         static synchronized ProgramRaster internalCreate(RenderScript rs, Builder b) {