Adding missing null-check.

Bug: 19850018
Change-Id: I17e1ac4c91fbf91ce53ab6a111aed854f8e4116e
diff --git a/InCallUI/src/com/android/incallui/VideoCallPresenter.java b/InCallUI/src/com/android/incallui/VideoCallPresenter.java
index 16a6e48..9bc0822 100644
--- a/InCallUI/src/com/android/incallui/VideoCallPresenter.java
+++ b/InCallUI/src/com/android/incallui/VideoCallPresenter.java
@@ -906,6 +906,9 @@
     public void onDeviceOrientationChanged(int orientation) {
         mDeviceOrientation = orientation;
         Point previewDimensions = getUi().getPreviewSize();
+        if (previewDimensions == null) {
+            return;
+        }
         Log.d(this, "onDeviceOrientationChanged: orientation=" + orientation + " size: "
                 + previewDimensions);
         changePreviewDimensions(previewDimensions.x, previewDimensions.y);