Remove max_streams_window_ in QuicStreamIdManager to make the code more readable. There is no need to have a dedicated member variable to store the window value because the computation of window is really simple and only used in one place. gfe-relnote: protected by gfe2_reloadable_flag_quic_enable_version_draft_25_v3 PiperOrigin-RevId: 305126280 Change-Id: Iee5f76af87dfe40c702ba74a6d21cdcc15ca2aa3