In the past, enabling the SoftAP would cause tethering to happen because
of some unfortunate side effects. This is no longer the case, and
using WifiManager for this purpose is not a good idea.
Bug: 30147602
Test: Can toggle tethering on/off via all of settings, quick settings,
and quick quick settings.
Change-Id: Iebbfc6c48b3e8e3fa52d235594ded3502f5801a3
(cherry picked from commit 26bd4efcaa)
090e9de648