beckham: sepolicy: Add mlstrustedsubject attribute to mods_app

This ensures that mods_app has the proper permission to access
/data/user_de/0/com.motorola.modservice/

Signed-off-by: Chenyang Zhong <zhongcy95@gmail.com>
Change-Id: Ie8caef2171dcdc02f160d0de545906e21085547c

sepolicy-mods/private/mods_app.te

 # ModService
 typeattribute mods_app coredomain;
+typeattribute mods_app mlstrustedsubject;
 
 app_domain(mods_app)
 net_domain(mods_app)