Make users of MtpServer fill in DeviceInfo field values

This is part of weaning apps off accessing system identifiers via
system properties API. Apps should use android.os.Build API instead.

Bug: 33700679
Test: Enable MTP mode then check that mtp-detect output same as before this commit
Change-Id: I4e6696cdee18b9c3e987c432c095911e85a997db
2 files changed