Virtual Display async mode is overridden

Virtual Display async setting is overridden by eglApi.c causing
stall during composition.

Set the async mode after eglCreateWindowSurface()

b/13139121

Change-Id: I336ca145552e387217cd8bea6e4b7f5f490a274d
Signed-off-by: Pierre Couillaud <pierre@broadcom.com>