SFR 460859 Missing FEC on lots of packets

Always enable FEC.

(cherry picked from commit 51ef1c872ffe8e7f9c14ea63f1c0f755d808bd8e)
SFR 460857 FEC data on AD is discarded due to NPE

When calculating Low Bit Rate Redunancy information (FEC) data on a
packet, initialize the decoder with the frequency rate currently in use
to prevent a NPE.

(cherry picked from commit 2c949541a9e6096608bd75e8125435ec8216b122)