[Thread] add Thread network permissions

Defines permissions for guarding access to Thread network API.

The permissions are also granted to shell for CTS tests, see the
instructions here: go/ctswrite#write-a-test-to-test-an-api-that-requires-system-permission

Design doc: go/thread-android-api

(cherry picked from commit 03aa71cd4b5eabe9310d3c4d4db10038b80853d1)

Bug: 262683651
Change-Id: Ib15d5589bbd304d68840ee52a193676d12110512