Make aggregation log statements debug level

[jtackaberry]

#16 was implemented (yay!) but Fluent Bit is now extremely verbose at info level:

time="2020-10-07T02:03:18Z" level=info msg="[kinesis ] Aggregated (1) records of size (895) with total size (895), partition key (cyWNsWj6)\n"
time="2020-10-07T02:03:23Z" level=info msg="[kinesis ] Aggregated (1) records of size (895) with total size (895), partition key (6pSaIX1r)\n"
time="2020-10-07T02:03:28Z" level=info msg="[kinesis ] Aggregated (1) records of size (895) with total size (895), partition key (GDBDb6IS)\n"
time="2020-10-07T02:03:33Z" level=info msg="[kinesis ] Aggregated (1) records of size (895) with total size (895), partition key (hgQY6LMV)\n"
time="2020-10-07T02:03:38Z" level=info msg="[kinesis ] Aggregated (1) records of size (895) with total size (895), partition key (k1FaRX9X)\n"

One imagines at higher load these lines would accumulate quickly. Perhaps this should be logged at debug?

[PettitWesley]

@jtackaberry Good idea

[zhonghui12]

It is released as part of https://github.com/aws/aws-for-fluent-bit/releases/tag/v2.9.0.