* Prevents calling endTracks() before all PMTs have been
processed.
* Adds a unique ID to the format of each track. This allows
the track selector to identify which track belongs to
each program. The format of each id is
"<program number>/<track output id>".
Note: This CL will break malformed TS files whose PAT
declares more PMTs than it actually contains, which
previously were supported. This does not apply for HLS
mode.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=146151642
