Add fwk_display_hwservice.

This hidl service provides information about vsync and hotplug
to vendor services which is required by at least some camera
hal implementations.

Test: VtsFwkDisplayServiceV1_0TargetTest
Test: no denials
Bug: 38311538
Change-Id: I64f0321e2832facf987057f0d48940e269d8e2d9
diff --git a/public/display_service_server.te b/public/display_service_server.te
new file mode 100644
index 0000000..c5839fa
--- /dev/null
+++ b/public/display_service_server.te
@@ -0,0 +1 @@
+add_hwservice(display_service_server, fwk_display_hwservice)