rtp session: Add test for collision loopback detection

Ignore further collisions if the remote SSRC change with ours, it's
probably because someone is sending us back the packets we send out.
8 jobs for rtpsession-collision-events in 24 minutes and 53 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Preparation
passed #88390
gst indent

00:00:31

passed #88389
manifest

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  Build
passed #88391
build fedora x86_64

00:08:23

 
  Test
passed #88392
check fedora

00:06:09

 
  Full Builds
passed #88393
build android arm64 api28

00:06:14

passed #88395
build cerbero cross win32

00:09:14

passed #88396
build cerbero cross win64

00:09:24

passed #88394
build cerbero fedora x86_64

00:09:33