[SPARK-54606][DOCS] Fix spark.eventLog.rolling.enabled deafult value

### What changes were proposed in this pull request?

It was enabled by default via SPARK-45771, but forgot to update the docs.

### Why are the changes needed?

Keep docs and code consistent.

### Does this PR introduce _any_ user-facing change?

No, except for correcting the docs.

### How was this patch tested?

Review, as it's a docs-only change.

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes apache#53339 from pan3793/SPARK-54606.

Authored-by: Cheng Pan <chengpan@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>

Author: pan3793

docs/configuration.md

@@ -1549,7 +1549,7 @@ Apart from these, the following properties are also available, and may be useful
 </tr>
 <tr>
   <td><code>spark.eventLog.rolling.enabled</code></td>
-  <td>false</td>
+  <td>true</td>
   <td>
     Whether rolling over event log files is enabled. If set to true, it cuts down each event
     log file to the configured size.