Update to the neteq_rtpplay utility to support RtcEventLog input files.

This CL adds support for simulating neteq using stored RTP packets as well as calls to GetAudio from an RtcEventLog, using the stored timestamps.
The type of the input file is detected automatically.
BUG=webrtc:4741

Review URL: https://codereview.webrtc.org/1316903002

Cr-Commit-Position: refs/heads/master@{#9886}
4 files changed