bind/java/SeqTest: use AndroidTestCase for Context.

To exercise the code path that uses Context given to Go.init.

Change-Id: Ied1f9efff325c711275a1969c373011c59e1d08d
Reviewed-on: https://go-review.googlesource.com/5750
Reviewed-by: David Crawshaw <crawshaw@golang.org>

bind/java/SeqTest.java

@@ -1,17 +1,17 @@
 package go;
 
 import android.test.suitebuilder.annotation.Suppress;
+import android.test.AndroidTestCase;
 import android.test.MoreAsserts;
 import java.util.Arrays;
 import java.util.Random;
 
 import go.testpkg.Testpkg;
 
-import junit.framework.TestCase;
-
-public class SeqTest extends TestCase {
-  static {
-    Go.init(null);
+public class SeqTest extends AndroidTestCase {
+  protected void setUp() throws Exception {
+    super.setUp();
+    Go.init(this.getContext());
   }
 
   public void testAdd() {