[Tether15] Allow system app to find TetheringManager

Bug: 144320246
Test: -build, flash, boot
      -OFF/ON hotspot

Change-Id: I8ce7ac5eb8198f0df4a2da426e3c56e8915e746a
diff --git a/private/service_contexts b/private/service_contexts
index fa52a05..ab66b82 100644
--- a/private/service_contexts
+++ b/private/service_contexts
@@ -196,6 +196,7 @@
 telephony.registry                        u:object_r:registry_service:s0
 telephony_ims                             u:object_r:radio_service:s0
 testharness                               u:object_r:testharness_service:s0
+tethering                                 u:object_r:tethering_service:s0
 textclassification                        u:object_r:textclassification_service:s0
 textservices                              u:object_r:textservices_service:s0
 time_detector                             u:object_r:timedetector_service:s0