The permission of Tethering is moved to a separate xml file,
add the xml module to the required field of tethering app.
Bug: 151213404
Test: TetheringTests
Merged-In: I40b45a0f1b44fba0b68e94811d14725a59ed4e59
Change-Id: I40b45a0f1b44fba0b68e94811d14725a59ed4e59