vr_wm hal client domain of graphics allocator.

Test: no denials seen
Bug: 36278706
Change-Id: I78d6fc84073a6ca006fb2b1ef95c73935cc9a1e0

public/vr_wm.te

 type vr_wm, domain;
 type vr_wm_exec, exec_type, file_type;
 
+hal_client_domain(vr_wm, hal_graphics_allocator)
+
 binder_use(vr_wm)
 binder_call(vr_wm, surfaceflinger)
 binder_call(vr_wm, virtual_touchpad)