tree 8efe335364c2612c9b3578351c88a541245d18cb
parent 0e7e32ab2c2670bc3d680bcec71f6fc6386815f8
author Lorenzo Colitti <lorenzo@google.com> 1611243220 +0900
committer Lorenzo Colitti <lorenzo@google.com> 1617186437 +0900

Make Tethering file NetworkRequests only if needed.

Currently, Tethering files NetworkRequests even when
config_tether_upstream_automatic is enabled. This is incorrect:
when the automatic upstream selection is enabled, the tethering
upstream should always follow the default network and there is
no need to file any requests.

These requests are harmful when tethering is not using cellular
as its upstream, because:

- If the device does not use mobile data always on, the request
  causes the cellular network to be brought up, causing power
  draw.
- Even if the device does use mobile data always on, the request
  causes the cellular network to come to the foreground, which
  allows all apps to access it, causing potential data usage.

Amend the existing testGetCurrentPreferredUpstream to cover these
changes, by making that test case always set automatic upstream
mode. This does not result in any loss of meaningful test
coverage, because getCurrentPreferredUpstream is only ever called
when chooseUpstreamAutomatically is enabled.

Bug: 173068192
Test: atest TetheringTests
Change-Id: I068a5338699a3ed04f24f97f785ea89ff5890e50