Don't throw exception if DeviceStateProviderImpl can't find required

sensor.

DeviceStateProviderImpl would thrown an exception when constructed if
the config it is based on required the presence of a Sensor that did not
exist. This changes the provider to ignore states with conditions that
have unknown sensors. If there are no states with known conditions it
defaults to the state with the lowest identifier.

Fixes: 186166148
Test: atest DeviceStateProviderImplTest
Change-Id: Iec73e33e2b464680fb9404863d11a26e9643248b