Remove unnecessary assert helpers from WindowTestBase

Bug: 116449554
Test: atest TaskStackContainersTests
Test: atest ZOrderingTests
Change-Id: I5baa7bf17561105ca2c724be1fee48755e0e1975
diff --git a/services/tests/servicestests/src/com/android/server/wm/TaskStackContainersTests.java b/services/tests/servicestests/src/com/android/server/wm/TaskStackContainersTests.java
index cd0f385..0e9a63c 100644
--- a/services/tests/servicestests/src/com/android/server/wm/TaskStackContainersTests.java
+++ b/services/tests/servicestests/src/com/android/server/wm/TaskStackContainersTests.java
@@ -19,6 +19,8 @@
 import static android.app.WindowConfiguration.ACTIVITY_TYPE_STANDARD;
 import static android.app.WindowConfiguration.WINDOWING_MODE_PINNED;
 
+import static com.google.common.truth.Truth.assertThat;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
@@ -68,7 +70,7 @@
     }
 
     @Test
-    public void testStackPositionChildAt() throws Exception {
+    public void testStackPositionChildAt() {
         // Test that always-on-top stack can't be moved to position other than top.
         final TaskStack stack1 = createTaskStackOnDisplay(mDisplayContent);
         final TaskStack stack2 = createTaskStackOnDisplay(mDisplayContent);
@@ -78,8 +80,8 @@
         final int stack1Pos = taskStackContainer.mChildren.indexOf(stack1);
         final int stack2Pos = taskStackContainer.mChildren.indexOf(stack2);
         final int pinnedStackPos = taskStackContainer.mChildren.indexOf(mPinnedStack);
-        assertGreaterThan(pinnedStackPos, stack2Pos);
-        assertGreaterThan(stack2Pos, stack1Pos);
+        assertThat(pinnedStackPos).isGreaterThan(stack2Pos);
+        assertThat(stack2Pos).isGreaterThan(stack1Pos);
 
         taskStackContainer.positionChildAt(WindowContainer.POSITION_BOTTOM, mPinnedStack, false);
         assertEquals(taskStackContainer.mChildren.get(stack1Pos), stack1);
@@ -93,7 +95,7 @@
     }
 
     @Test
-    public void testStackPositionBelowPinnedStack() throws Exception {
+    public void testStackPositionBelowPinnedStack() {
         // Test that no stack can be above pinned stack.
         final TaskStack stack1 = createTaskStackOnDisplay(mDisplayContent);
 
@@ -101,7 +103,7 @@
 
         final int stackPos = taskStackContainer.mChildren.indexOf(stack1);
         final int pinnedStackPos = taskStackContainer.mChildren.indexOf(mPinnedStack);
-        assertGreaterThan(pinnedStackPos, stackPos);
+        assertThat(pinnedStackPos).isGreaterThan(stackPos);
 
         taskStackContainer.positionChildAt(WindowContainer.POSITION_TOP, stack1, false);
         assertEquals(taskStackContainer.mChildren.get(stackPos), stack1);