[Thread] add ot-daemon to com.android.tethering

ot-daemon is a dependency of the new Thread feature. This commit
add the ot-daemon binary and init rc file to the Tethering module.
Note that the ot-daemon service is default disabled and versioned
init rc file is used to ensure that this service won't be started
before Android U.

This is expected to increase the size of "com.android.tethering.capex"
by around 400 KB.

Manual verification:
1. on Android T (33) CF device, the ot-daemon service is not started
   after device boots; It reports service not found error when trying
   to start the ot-daemon service with adb shell command "start
   ot-daemon"
2. on Android U (34) CF device, the ot-daemon service is not started
   after device boots; It can be started with shell comamnd "start
   ot-daemon" but then failed because of missing sepolicy rules as
   expected

Test: see above manual verification note
Bug: 296211911
Change-Id: I222e2bbcc2ad0be2beec9f5f3406e7144d314370