Added system_server_dumper service.

It will be used to dump system_server data that is not associated
with any service.

Test: adb shell dumpsys system_server
Bug: 163921395

Change-Id: I5719f7cd3a9022dc0ab12a3b3b22487e2b4866e0
diff --git a/private/service_contexts b/private/service_contexts
index da3f98e..55f7c5c 100644
--- a/private/service_contexts
+++ b/private/service_contexts
@@ -221,6 +221,7 @@
 SurfaceFlinger                            u:object_r:surfaceflinger_service:s0
 suspend_control                           u:object_r:system_suspend_control_service:s0
 system_config                             u:object_r:system_config_service:s0
+system_server_dumper                      u:object_r:system_server_dumper_service:s0
 system_update                             u:object_r:system_update_service:s0
 task                                      u:object_r:task_service:s0
 telecom                                   u:object_r:telecom_service:s0