Earlier the pid/tl0 was incorrectly reinitialized upon encoder reconfiguration,
and this fix was implemented to mitigate that. This fix can however guess wrong
and cause a valid stream to be interupted.
BUG=webrtc:7920
Review-Url: https://codereview.webrtc.org/2969043002
Cr-Commit-Position: refs/heads/master@{#19268}