composer: surface screen part status

The overview of the architecture here looks like this. Our
TradeInMode service will make a call to surfaceComposer which will then
ask surfaceFlinger to return the displayIdentification info. We can
gather all the physical display ID's through DisplayControl

Flag: com.android.tradeinmode.flags.trade_in_mode_2025q4
Test: manual testing on pixel fold
Change-Id: I3234d45aa3f9c538a3ba3f01f55428a935267e30