Replace cloud-gce with discovery-gce

Related to #13815

docs/plugins/discovery-gce.asciidoc

@@ -61,7 +61,7 @@ You can use {ref}/modules-network.html[core network host settings] or
 [[discovery-gce-network-host]]
 ==== GCE Network Host
 
-When the `cloud-gce` plugin is installed, the following are also allowed
+When the `discovery-gce` plugin is installed, the following are also allowed
 as valid network host settings:
 
 [cols="<,<",options="header",]

docs/reference/modules/network.asciidoc

@@ -54,7 +54,7 @@ provided network interface. For example `_en0:ipv6_`.
 When the `discovery-ec2` plugin is installed, you can use
 {plugins}/discovery-ec2-discovery.html#discovery-ec2-network-host[ec2 specific host settings].
 
-When the `cloud-gce` plugin is installed, you can use
+When the `discovery-gce` plugin is installed, you can use
 {plugins}/discovery-gce-network-host.html[gce specific host settings].