Remove QuicStreamIdManager::IsIncomingStream() as it's hard coded. Also QuicSession doesn't need the indirectness. QuicUtils should be the single source of truth. gfe-relnote: no behavior change. not protected. PiperOrigin-RevId: 305518573 Change-Id: I926c93ccd33f12c694b823d764a88d13df3e6c94