Using rotate split layout while split active

While startEnterSplit, if mRotateSplitLayout is exist then it
means we got rotation changed but still not update mSplitLayout
until onDisplayConfigurationChanged callback.

We should using mRotateSplitLayout on this case to ensure the
DisplayLayout is right.

Fix: 190028155
Test: close auto-rotation, open landscape app then
      enable split screen
Change-Id: I68cf0ca3d10ed500100af843e7ed5afdc090b8fc