Rename gfe2_restart_flag_always_promote_chunk_if_coalesced_2 and remove "enabling_blocked_by".
Rename gfe2_restart_flag_always_promote_chunk_if_coalesced_2 and remove "enabling_blocked_by".

Protected by FLAGS_gfe2_restart_flag_always_promote_chunk_if_coalesced_3.

PiperOrigin-RevId: 350136495
Change-Id: Icc7ad8036207dac743bc5d6c0f34c63bed16d48f

google/quiche,google/quiche,google/quiche,google/quiche