in_cloudwatch_logs: Use storage instead of state_file in some testcases
in_cloudwatch_logs: Use storage instead of state_file in some testcases

Signed-off-by: Hiroshi Hatake <a476a6e5b5893650242fbf0b2961500a9bd9032e@clear-code.com>

ryotarai/fluent-plugin-cloudwatch-logs