Tuner API: modify permission check

1. remove @RequiresPermission of non-static methods since it checks
permission in the constructor.

2. check permission in system process instead of app process, such as:
https://cs.corp.google.com/master-arc-dev/frameworks/base/services/core/java/com/android/server/tv/tunerresourcemanager/TunerResourceManagerService.java?type=cs&q=ACCESS_TV_DESCRAMBLER&g=0&l=684

Bug: 149785806
Test: mmm;
Change-Id: I034b5a75f7c8962dbc6c92a573f999a2853082ed