Update default value for flush.timeout and flush.min_events (elastic#…

…7192)

* Update default value for flush.timeout

Checking the code, it seems the default `flush.timeout` is `1s` - https://github.com/elastic/beats/blob/v6.2.4/libbeat/publisher/queue/memqueue/config.go#L14-L18 - instead of `0s` . Change needs some dev review to confirm!

* Updated default value for flush.min_events

flush.min_events setting the default to 2048

* Corrected typo

The default `values` is 1s. -> The default `value` is 1s.

(cherry picked from commit dca6ad8)

libbeat/docs/queueconfig.asciidoc

@@ -67,15 +67,15 @@ Minimum number of events required for publishing. If this value is set to 0, the
 output can start publishing events without additional waiting times. Otherwise
 the output has to wait for more events to become available.
 
-The default value is 0.
+The default value is 2048.
 
 [float]
 ===== `flush.timeout`
 
 Maximum wait time for `flush.min_events` to be fulfilled. If set to 0s, events
 will be immediately available for consumption.
 
-The default values is 0s.
+The default value is 1s.
 
 [float]
 [[configuration-internal-queue-spool]]