Fix storage.metrics option to be enabled by default

Signed-off-by: motohiro.nakamura <motohiro.nakamura@lycorp.co.jp>

administration/buffering-and-storage.md

@@ -120,7 +120,7 @@ The Service section refers to the section defined in the main [configuration fil
 | storage.checksum | Enable the data integrity check when writing and reading data from the filesystem. The storage layer uses the CRC32 algorithm. | Off |
 | storage.max\_chunks\_up | If the input plugin has enabled `filesystem` storage type, this property sets the maximum number of Chunks that can be `up` in memory. *This is the setting to use to control memory usage when you enable `storage.type filesystem`*. | 128 |
 | storage.backlog.mem\_limit | If _storage.path_ is set, Fluent Bit will look for data chunks that were not delivered and are still in the storage layer, these are called _backlog_ data. _Backlog chunks_ are filesystem chunks that were left over from a previous Fluent Bit run; chunks that could not be sent before exit that Fluent Bit will pick up when restarted. Fluent Bit will check the `storage.backlog.mem_limit` value against the current memory usage from all `up` chunks for the input. If the `up` chunks currently consume less memory than the limit, it will bring the _backlog_ chunks up into memory so they can be sent by outputs. | 5M |
-| storage.metrics | If `http_server` option has been enabled in the main `[SERVICE]` section, this option registers a new endpoint where internal metrics of the storage layer can be consumed. For more details refer to the [Monitoring](monitoring.md) section. | off |
+| storage.metrics | If `http_server` option has been enabled in the main `[SERVICE]` section, this option registers a new endpoint where internal metrics of the storage layer can be consumed. For more details refer to the [Monitoring](monitoring.md) section. | On |
 | storage.delete_irrecoverable_chunks | When enabled, [irrecoverable chunks](./buffering-and-storage.md#irrecoverable-chunks) will be deleted during runtime, and any other irrecoverable chunk located in the configured storage path directory will be deleted when Fluent-Bit starts. | Off |
 
 a Service section will look like this: