[apm]: Add changes to storage limit behavior based on the Discard On Write Failure config

Author: isaacaflores2

docs/en/observability/apm/configure/sampling.asciidoc

@@ -67,7 +67,7 @@ This final policy is used to catch remaining trace events that don't match a str
 === Storage limit
 The amount of storage space allocated for trace events matching tail sampling policies. Caution: Setting this limit higher than the allowed space may cause APM Server to become unhealthy.
 
-If the configured storage limit is insufficient, it logs "configured storage limit reached". The event will bypass sampling and will always be indexed when storage limit is reached.
+If the configured storage limit is insufficient, it logs "configured storage limit reached". When the storage limit is reached, the event will be indexed or discarded based on the <<sampling-tail-discard_on_write_failure-{input-type},Discard On Write Failure>> configuration.
 
 Default: `3GB`. (text)