interceptor: avoid concurrency on the command log

Using the protobuf util to serialize to the stream can lead to corrupted
intermediate logs due to concurrency. Ensure only one process is writing
to the log file at a time by directly writing to the log file in a
single write call.

Signed-off-by: Matthias Maennich <maennich@google.com>
Change-Id: I043f349c130cfe307bd51030a1708c6afd122fdb
1 file changed