changing texcoord from vec4 to vec2 for perf reasons.

Change-Id: I18a9f94694f8977db79d9cb42d0a7d88c41c9c24
diff --git a/carousel/java/com/android/ex/carousel/CarouselRS.java b/carousel/java/com/android/ex/carousel/CarouselRS.java
index 14a69bd..e086372 100644
--- a/carousel/java/com/android/ex/carousel/CarouselRS.java
+++ b/carousel/java/com/android/ex/carousel/CarouselRS.java
@@ -74,7 +74,7 @@
     private float[] mUp = new float[3];
 
     private static final String mSingleTextureShader = new String(
-            "varying vec4 varTex0;" +
+            "varying vec2 varTex0;" +
             "void main() {" +
             "vec2 t0 = varTex0.xy;" +
             "vec4 col = texture2D(UNI_Tex0, t0);" +
@@ -82,7 +82,7 @@
             "}");
 
     private static final String mMultiTextureShader = new String(
-            "varying vec4 varTex0;" +
+            "varying vec2 varTex0;" +
             "void main() {" +
             "vec2 t0 = varTex0.xy;" +
             "vec4 col = texture2D(UNI_Tex0, t0);" +