Disable seamless rotation when nav bar jumps.

When the nav bar visually moves on rotation, we want
to disable seamless rotation. We could investigate later
if it could be made to work.

Test: Try rotating camera video view on tablet.
Bug: 31817280
Change-Id: Ie13d7eaafd8bb66c8db574cd81d76fa9ca860e51

services/core/java/com/android/server/policy/PhoneWindowManager.java

@@ -7919,6 +7919,12 @@ public class PhoneWindowManager implements WindowManagerPolicy {
         if (oldRotation == mUpsideDownRotation || newRotation == mUpsideDownRotation) {
             return false;
         }
+        // If the navigation bar can't change sides, then it will
+        // jump when we change orientations and we don't rotate
+        // seamlessly.
+        if (!mNavigationBarCanMove) {
+            return false;
+        }
         int delta = newRotation - oldRotation;
         if (delta < 0) delta += 4;
         // Likewise we don't rotate seamlessly for 180 degree rotations