Make testSetTextLong() wait for its work to finish.

Previously, rendering the long text run in the test could go on
during the setUp of the next test method, making the next test to
time out and fail.

Now, we just wait for the work to finish before we declare the test
done.

Bug: 18088201
Change-Id: I3dfd64ae1adc916bccd399e1cca67a9d388666c4
(cherry picked from commit f08da5962f03bcdf92fc5d34b7884a48c0aebab1)
diff --git a/tests/tests/widget/src/android/widget/cts/TextViewTest.java b/tests/tests/widget/src/android/widget/cts/TextViewTest.java
index 24b8fdb..480e1a6 100644
--- a/tests/tests/widget/src/android/widget/cts/TextViewTest.java
+++ b/tests/tests/widget/src/android/widget/cts/TextViewTest.java
@@ -2845,15 +2845,19 @@
         assertEquals(1, mTextView.getImeActionId());
     }
 
-    @UiThreadTest
     public void testSetTextLong() {
-        final int MAX_COUNT = 1 << 21;
-        char[] longText = new char[MAX_COUNT];
-        for (int n = 0; n < MAX_COUNT; n++) {
-            longText[n] = 'm';
-        }
-        mTextView = findTextView(R.id.textview_text);
-        mTextView.setText(new String(longText));
+        mActivity.runOnUiThread(new Runnable() {
+            public void run() {
+                final int MAX_COUNT = 1 << 21;
+                char[] longText = new char[MAX_COUNT];
+                for (int n = 0; n < MAX_COUNT; n++) {
+                    longText[n] = 'm';
+                }
+                mTextView = findTextView(R.id.textview_text);
+                mTextView.setText(new String(longText));
+            }
+        });
+        mInstrumentation.waitForIdleSync();
     }
 
     @UiThreadTest