Upgrade with Device Owner: Allow permission control

Devices that have had a Device Owner (i.e. fully-managed devices),
when upgrading to Android S, should maintain the ability for the admin
to grant sensors-related permissions.

This new upgrade step takes care of this, and bumps the
DevicePolicyManagerService data version to 2.

Bug: 181009337
Bug: 158735247
Test: FrameworksServicesTests:PolicyVersionUpgraderTest
Change-Id: I2aea7fd8d2ec2a3a4cb16f6bc0fee45f3c04ad4c