Add service 'overlay' to service_contexts

The 'overlay' service is the Overlay Manager Service, which tracks
packages and their Runtime Resource Overlay overlay packages.

Change-Id: I897dea6a32c653d31be88a7b3fc56ee4538cf178
Co-authored-by: Martin Wallgren <martin.wallgren@sonymobile.com>
Signed-off-by: Zoran Jovanovic <zoran.jovanovic@sonymobile.com>
Bug: 31052947
Test: boot the Android framework

private/service_contexts

@@ -103,6 +103,7 @@ network_time_update_service               u:object_r:network_time_update_service
 nfc                                       u:object_r:nfc_service:s0
 notification                              u:object_r:notification_service:s0
 otadexopt                                 u:object_r:otadexopt_service:s0
+overlay                                   u:object_r:overlay_service:s0
 package                                   u:object_r:package_service:s0
 permission                                u:object_r:permission_service:s0
 persistent_data_block                     u:object_r:persistent_data_block_service:s0

public/idmap.te

@@ -8,3 +8,4 @@ allow idmap resourcecache_data_file:file { getattr read write };
 
 # Open and read from target and overlay apk files passed by argument.
 allow idmap apk_data_file:file r_file_perms;
+allow idmap apk_data_file:dir search;

public/service.te

@@ -96,6 +96,7 @@ type network_score_service, system_api_service, system_server_service, service_m
 type network_time_update_service, system_server_service, service_manager_type;
 type notification_service, app_api_service, system_server_service, service_manager_type;
 type otadexopt_service, system_server_service, service_manager_type;
+type overlay_service, system_server_service, service_manager_type;
 type package_service, app_api_service, system_server_service, service_manager_type;
 type permission_service, app_api_service, system_server_service, service_manager_type;
 type persistent_data_block_service, system_api_service, system_server_service, service_manager_type;