Add owneship of tethering module

Bug: 158961959
Test: build/make/tools/checkowners.py packages/NetworkStack/OWNERS
Test: ./build/make/tools/checkowners.py \
frameworks/base/packages/Tethering/OWNERS

Merged-In: I13b291e5db6a8a8c9f2bfa477acabaea250aa48c
Change-Id: I13b291e5db6a8a8c9f2bfa477acabaea250aa48c
1 file changed