Fix flakiness in testRequestLayoutWithTemporaryDetach

Removed unrelated assertion in the test which added flakiness
on watches. On watches, ListView.getChildAt().requestFocus()
gains focus on the child and immidiately after, it loses focus.

Raised a seprate bug 62913319 to track that.

Change-Id: Ifdfd68a9c44d5b3ea50e6fad2425bc2660a247fc
Fixes: 62843881
Test: cts-tradefed run singleCommand cts-dev
--m CtsWidgetTestCases
--test
android.widget.cts.ListViewTest#testRequestLayoutWithTemporaryDetach
(cherry picked from commit 942f96842d5179e6137d3fbb3c24f07ad259dc6b)
diff --git a/tests/tests/widget/src/android/widget/cts/ListViewTest.java b/tests/tests/widget/src/android/widget/cts/ListViewTest.java
index 8cd85b1..d97c66e 100644
--- a/tests/tests/widget/src/android/widget/cts/ListViewTest.java
+++ b/tests/tests/widget/src/android/widget/cts/ListViewTest.java
@@ -931,10 +931,6 @@
         assertNotNull(childView1);
         assertNotNull(childView2);
 
-        // Make sure that the childView1 has focus.
-        mActivityRule.runOnUiThread(childView1::requestFocus);
-        PollingCheck.waitFor(1000, childView1::isFocused);
-
         // Make sure that ListView#requestLayout() is optimized when nothing is changed.
         WidgetTestUtils.runOnMainAndDrawSync(mActivityRule, mListView, mListView::requestLayout);
         assertEquals(childView0, mListView.getChildAt(0));