Do RS caching the same way HardwareRenderer does.
Eliminates the need for an application context for caching.

Change-Id: I4374738083b5eb4ce983d2cb5409428e3668c423
diff --git a/core/java/android/app/ActivityThread.java b/core/java/android/app/ActivityThread.java
index bf632a9..5d1d461 100644
--- a/core/java/android/app/ActivityThread.java
+++ b/core/java/android/app/ActivityThread.java
@@ -78,6 +78,7 @@
 import android.view.Window;
 import android.view.WindowManager;
 import android.view.WindowManagerImpl;
+import android.renderscript.RenderScript;
 
 import com.android.internal.os.BinderInternal;
 import com.android.internal.os.RuntimeInit;
@@ -3779,6 +3780,7 @@
                 appContext.init(info, null, this);
 
                 HardwareRenderer.setupDiskCache(appContext.getCacheDir());
+                RenderScript.setupDiskCache(appContext.getCacheDir());
             }
         } catch (RemoteException e) {
             // Ignore