Force update orientation handler for initial recents view state.

Force execute updateSizeAndPadding at onGestureAnimationStart to ensure
there has computed the initial task size even if orientation didn't
changed.

Bug: 228565696
Test: run "atest NexusLauncherTests" on tablet device.
Change-Id: I175754a68e91039dffdfd4035414885417882a07

quickstep/src/com/android/quickstep/views/RecentsView.java

@@ -2092,6 +2092,9 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         if (mOrientationState.setGestureActive(true)) {
             setLayoutRotation(rotationTouchHelper.getCurrentActiveRotation(),
                     rotationTouchHelper.getDisplayRotation());
+            // Force update to ensure the initial task size is computed even if the orientation has
+            // not changed.
+            updateSizeAndPadding();
         }
 
         showCurrentTask(runningTaskInfo);