Add config_tether_* and entitlement resources

Copies config_tether_* and entitlement resources from
framework/base/core/res to tethering package. Will have
follow up changes to move overlay and switch tethering to
use this internal resource. duplicated resource in framework
will be removed after fixing all of users(e.g. test, TetherUtil,
Settings, ....).

Bug: 147399354
Test: build

Change-Id: I2a77e5070d53566d5ec3697358a6dbbebb4ff59f