updated regex for network and subnetwork based on codeassist comment

Author: Daisyprakash

modules/gke-autopilot-cluster/metadata.display.yaml

@@ -316,7 +316,7 @@ spec:
         network:
           name: network
           title: Network
-          regexValidation: ^[a-z][a-z0-9-]{0,60}[a-z0-9]$
+          regexValidation: ^[a-z]([a-z0-9-]{0,60}[a-z0-9])?$
           validation: Network name must start with a lowercase letter followed by up to 62 lowercase letters, numbers, or hyphens and cannot end with a hyphen.
           altDefaults:
             - type: ALTERNATE_TYPE_DC
@@ -471,7 +471,7 @@ spec:
         subnetwork:
           name: subnetwork
           title: Subnetwork
-          regexValidation: ^[a-z][a-z0-9-]{0,60}[a-z0-9]$
+          regexValidation: ^[a-z]([a-z0-9-]{0,60}[a-z0-9])?$
           validation: Network name must start with a lowercase letter followed by up to 62 lowercase letters, numbers, or hyphens and cannot end with a hyphen.
           altDefaults:
             - type: ALTERNATE_TYPE_DC

modules/gke-standard-cluster/metadata.display.yaml

@@ -416,7 +416,7 @@ spec:
         network:
           name: network
           title: Network
-          regexValidation: ^[a-z][a-z0-9-]{0,60}[a-z0-9]$
+          regexValidation: ^[a-z]([a-z0-9-]{0,60}[a-z0-9])?$
           validation: Network name must start with a lowercase letter followed by up to 62 lowercase letters, numbers, or hyphens and cannot end with a hyphen.
           altDefaults:
             - type: ALTERNATE_TYPE_DC
@@ -992,7 +992,7 @@ spec:
         subnetwork:
           name: subnetwork
           title: Subnetwork
-          regexValidation: ^[a-z][a-z0-9-]{0,60}[a-z0-9]$
+          regexValidation: ^[a-z]([a-z0-9-]{0,60}[a-z0-9])?$
           validation: Network name must start with a lowercase letter followed by up to 62 lowercase letters, numbers, or hyphens and cannot end with a hyphen.
           altDefaults:
             - type: ALTERNATE_TYPE_DC