Up until now, our approach to validating incoming RTP payloads and
dropping invalid ones has been to apply the preening function inside
l1sap_tch_rts_ind(), at the point of dequeueing from the DL input queue.
However, there are some RTP formats where we need to strip one byte
of header from the payload before passing the rest to our innards:
there is RFC 5993 for HR codec, and there also exists a non-standard
extension (rtp_traulike) that does a similar deal for FR and EFR.
Because of alignment issues, it will be more efficient (avoids memmove)
if we can do this header octet stripping before we copy the payload
into msgb - but doing so requires that we move this preening logic
to the point of RTP input before enqueueing. Make this change.
Related: OS#5688
Change-Id: I7fc99aeecba8303b56d397b8952de5eea82b301e
Mychaela N. Falconia