Add API support for 3D allocations.

Change-Id: I19c525f90135d83caec545e77e8f61a957d220ee
diff --git a/graphics/java/android/renderscript/Type.java b/graphics/java/android/renderscript/Type.java
index a707df2..b36aee2 100644
--- a/graphics/java/android/renderscript/Type.java
+++ b/graphics/java/android/renderscript/Type.java
@@ -244,6 +244,14 @@
             return this;
         }
 
+        public Builder setZ(int value) {
+            if(value < 1) {
+                throw new RSIllegalArgumentException("Values of less than 1 for Dimension Z are not valid.");
+            }
+            mDimZ = value;
+            return this;
+        }
+
         public Builder setMipmaps(boolean value) {
             mDimMipmaps = value;
             return this;