SEPolicy updates for DeviceConfig Service.

Add a DeviceConfig service in system_server to edit configuration flags.
This is intended to be a command line tool for local overrides and/or
tool for tests that adopt shell permissions.

Test: None
Bug:109919982
Bug:113101834
Change-Id: Ib7bed752849b1ed102747e3202dd7aed48d2c6d5
diff --git a/private/service_contexts b/private/service_contexts
index 7f1b38f..43479b3 100644
--- a/private/service_contexts
+++ b/private/service_contexts
@@ -38,6 +38,7 @@
 cpuinfo                                   u:object_r:cpuinfo_service:s0
 crossprofileapps                          u:object_r:crossprofileapps_service:s0
 dbinfo                                    u:object_r:dbinfo_service:s0
+device_config                             u:object_r:device_config_service:s0
 device_policy                             u:object_r:device_policy_service:s0
 device_identifiers                        u:object_r:device_identifiers_service:s0
 deviceidle                                u:object_r:deviceidle_service:s0