Update wearable_sensing_service to app_api_service

Being a system_api_service prevents non-privileged apps from getting a reference to WearableSensingManager via Context#getSystemService (it returns null). CTS tests are run as non-privileged apps, so we need this change to properly test the API.

The API methods are protected by a signature|privileged permission. CTS tests can gain this permission by adopting the Shell's permission identity, but it can't get around the SELinux policy.

wearable_sensing_service is mostly modelled after ambient_context_service, which is an app_api_service, so we believe this change is fine from a security's perspective.

Test: A CTS test can get a WearableSensingManager via Context#getSystemService after this change.

Change-Id: I9d854353f48ff7b3fa5a07527bee0bcc83cb6236
diff --git a/private/service.te b/private/service.te
index 2f5241c..e97eb8c 100644
--- a/private/service.te
+++ b/private/service.te
@@ -27,4 +27,4 @@
 ')
 
 type uce_service,                   service_manager_type;
-type wearable_sensing_service,      system_api_service, system_server_service, service_manager_type;
+type wearable_sensing_service,      app_api_service, system_server_service, service_manager_type;