Data sent to APM-Server can get corrupted if more than one log events are processed concurrently

[lahsivjar]

1. Metadata is created from the data agent sends as a slice of bytes by using bytes#Cut (ref)
2. While processing the log events, we append the processed log event to the metadata slice (ref)

Given that appending to the metadata slice in 2 doesn't trigger a reallocation and 2 log events are being processed concurrently, it is possible for the data to get corrupted.