Tail-based sampling currently doesn't expose a configuration option to select the behavior when a batch of events fail to be processed. There are 2 options to choose from for failure cases:

1. Index on failure
2. Drop on failure

Index on failure is the default behavior of APM-Server. The code does have the option to choose drop on failure however, it is not exposed as a config option (ref)

Also update the docs created in #11126