Update gpu_driver_version to say driver autoinstallation is default on (#13748) (#22506)

[upstream:52fa31aab1fe4248f269115327955207755c9dff]

Signed-off-by: Modular Magician <[email protected]>

Author: modular-magician

website/docs/r/container_cluster.html.markdown

@@ -1106,7 +1106,7 @@ sole_tenant_config {
 
 * `gpu_driver_version` (Required) - Mode for how the GPU driver is installed.
     Accepted values are:
-    * `"GPU_DRIVER_VERSION_UNSPECIFIED"`: Default value is to not install any GPU driver.
+    * `"GPU_DRIVER_VERSION_UNSPECIFIED"`: Default value is to install the "Default" GPU driver. Before GKE `1.30.1-gke.1156000`, the default value is to not install any GPU driver.
     * `"INSTALLATION_DISABLED"`: Disable GPU driver auto installation and needs manual installation.
     * `"DEFAULT"`: "Default" GPU driver in COS and Ubuntu.
     * `"LATEST"`: "Latest" GPU driver in COS.