Remove ActivityThread from deviceconfig.java

As part of moving DeviceConfig.java to packages/modules/ConfigInfrastructure.
Need to move activity thread dependency to setting.config as the new
module will not have access to hidden apis (ActivityThread).

Test: m
Bug: 258220607
Change-Id: Ib7b20caaec128d64908349918ec7bce9a53cc2e6