DO NOT MERGE: Disable tethering.inprocess APEX in stable branch

Disable the tethering.inprocess APEX in stable API module
branch, as it builds against unstable API stubs that cannot be
built there.

Ignore-AOSP-First: this allows avoiding merge conflicts in AOSP
Bug: 190249673
Change-Id: I474faea75293f33fa4cd53c7619087503c658b74
Test: m
1 file changed