Add optional metadata to initiliaze the render threat.

The render threat is likely to break your application if you initiate it.
As such it must be explicitely requested using the following meta-data
tag in your manifest's application tag:

<meta-data android:name="android.graphics.renderThread" android:value="true" />

Change-Id: Ibf0a48af2a0d091562bf6907eac970e3d1d601c4
diff --git a/tests/HwAccelerationTest/AndroidManifest.xml b/tests/HwAccelerationTest/AndroidManifest.xml
index 5bbcce3..643cb8d 100644
--- a/tests/HwAccelerationTest/AndroidManifest.xml
+++ b/tests/HwAccelerationTest/AndroidManifest.xml
@@ -30,6 +30,8 @@
         android:label="HwUi"
         android:hardwareAccelerated="true">
 
+        <meta-data android:name="android.graphics.renderThread" android:value="true" />
+
         <activity
                 android:name="PaintDrawFilterActivity"
                 android:label="_DrawFilter">