docs(bigquery): update retry helper comments as suggested

Author: jinseopkim0

java-bigquery/google-cloud-bigquery/src/main/java/com/google/cloud/bigquery/BigQueryImpl.java

@@ -2414,7 +2414,7 @@ private static boolean isRetryErrorCodeHttpNotFound(BigQueryRetryHelperException
   }
 
   /**
-   * Helper to retrieve the retry algorithm wrapped for safe HTTP 5xx error retries.
+   * Helper to retrieve the retry algorithm wrapped for HTTP error retries.
    *
    * <p>This delegates to {@link BigQueryRetryHelper#maybeWrapForHttpRetry} to ensure safe
    * conditional wrapping of the default algorithm while leaving custom user algorithms untouched.

java-bigquery/google-cloud-bigquery/src/main/java/com/google/cloud/bigquery/BigQueryRetryHelper.java

@@ -123,7 +123,7 @@ private static <V> V run(
 
   /**
    * Conditionally wraps the provided retry algorithm with a wrapper that retries on transient HTTP
-   * 5xx errors (500, 502, 503, 504).
+   * errors.
    *
    * <p>Wrapping only occurs if the provided algorithm is the default {@link
    * BigQueryBaseService#DEFAULT_BIGQUERY_EXCEPTION_HANDLER}. Custom user-defined retry algorithms