This removes noisy data from the dump files and allows updating less
dump files if a format field is added, removed or updated.
PiperOrigin-RevId: 297617138
Note: The dump files will need updating again when the extractors
are modified to only set the appropriate bitrate. Enhancing the
test first is nice, because it means that in subsequent CLs the
dump file updates can be used to quickly see what's changed in
the output.
PiperOrigin-RevId: 297188367