gfe-relnote: In quic_framer.cc, replace PacketNumberIntervalLength(interval) by interval.Length(). Not protected.
gfe-relnote: In quic_framer.cc, replace PacketNumberIntervalLength(interval) by interval.Length(). Not protected.

Also took the chance to clang-format this file.

PiperOrigin-RevId: 278619379
Change-Id: I7ab2b3ff8469fd34bfb4d987539e97b8a23d4cb1

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