chore: Update discovery artifacts (#1375)

## Deleted keys were detected in the following stable discovery artifacts:
servicenetworking v1 https://github.com/googleapis/google-api-python-client/commit/c0ad756013c602597e477bc0e22e7b2771689214

## Deleted keys were detected in the following pre-stable discovery artifacts:
retail v2alpha https://github.com/googleapis/google-api-python-client/commit/c9d7a149295d827110c789e464b4f97edc13cbaa
servicenetworking v1beta https://github.com/googleapis/google-api-python-client/commit/c0ad756013c602597e477bc0e22e7b2771689214

## Discovery Artifact Change Summary:
feat(composer): update the api https://github.com/googleapis/google-api-python-client/commit/c2cb2746320fa7b6c1536028794f53576c0f1ddd
feat(compute): update the api https://github.com/googleapis/google-api-python-client/commit/2cdcd0a21223a229e711778a3cf1b38c63521d96
feat(dfareporting): update the api https://github.com/googleapis/google-api-python-client/commit/73f7d790e1585322547fe7cb39c8f36e7b400121
feat(dialogflow): update the api https://github.com/googleapis/google-api-python-client/commit/8edd852f294eaccfa6a0e7288d54a2d751f53506
feat(retail): update the api https://github.com/googleapis/google-api-python-client/commit/c9d7a149295d827110c789e464b4f97edc13cbaa
feat(sasportal): update the api https://github.com/googleapis/google-api-python-client/commit/12683cabbf8deaf0a884147b98c30345786874a6
feat(servicenetworking): update the api https://github.com/googleapis/google-api-python-client/commit/c0ad756013c602597e477bc0e22e7b2771689214
diff --git a/docs/dyn/compute_v1.vpnGateways.html b/docs/dyn/compute_v1.vpnGateways.html
index 8bd91ce..8f78fba 100644
--- a/docs/dyn/compute_v1.vpnGateways.html
+++ b/docs/dyn/compute_v1.vpnGateways.html
@@ -156,12 +156,12 @@
           "network": "A String", # URL of the network to which this VPN gateway is attached. Provided by the client when the VPN gateway is created.
           "region": "A String", # [Output Only] URL of the region where the VPN gateway resides.
           "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
-          "vpnInterfaces": [ # A list of interfaces on this VPN gateway.
+          "vpnInterfaces": [ # The list of VPN interfaces associated with this VPN gateway.
             { # A VPN gateway interface.
-              "id": 42, # The numeric ID of this VPN gateway interface.
-              "interconnectAttachment": "A String", # URL of the interconnect attachment resource. When the value of this field is present, the VPN Gateway will be used for IPsec-encrypted Cloud Interconnect; all Egress or Ingress traffic for this VPN Gateway interface will go through the specified interconnect attachment resource.
-                  # Not currently available in all Interconnect locations.
-              "ipAddress": "A String", # [Output Only] The external IP address for this VPN gateway interface.
+              "id": 42, # [Output Only] Numeric identifier for this VPN interface associated with the VPN gateway.
+              "interconnectAttachment": "A String", # URL of the VLAN attachment (interconnectAttachment) resource for this VPN gateway interface. When the value of this field is present, the VPN gateway is used for IPsec-encrypted Cloud Interconnect; all egress or ingress traffic for this VPN gateway interface goes through the specified VLAN attachment resource.
+                  # Not currently available publicly.
+              "ipAddress": "A String", # [Output Only] IP address for this VPN interface associated with the VPN gateway. The IP address could be either a regional external IP address or a regional internal IP address. The two IP addresses for a VPN gateway must be all regional external or regional internal IP addresses. There cannot be a mix of regional external IP addresses and regional internal IP addresses. For IPsec-encrypted Cloud Interconnect, the IP addresses for both interfaces could either be regional internal IP addresses or regional external IP addresses. For regular (non IPsec-encrypted Cloud Interconnect) HA VPN tunnels, the IP address must be a regional external IP address.
             },
           ],
         },
@@ -325,12 +325,12 @@
   "network": "A String", # URL of the network to which this VPN gateway is attached. Provided by the client when the VPN gateway is created.
   "region": "A String", # [Output Only] URL of the region where the VPN gateway resides.
   "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
-  "vpnInterfaces": [ # A list of interfaces on this VPN gateway.
+  "vpnInterfaces": [ # The list of VPN interfaces associated with this VPN gateway.
     { # A VPN gateway interface.
-      "id": 42, # The numeric ID of this VPN gateway interface.
-      "interconnectAttachment": "A String", # URL of the interconnect attachment resource. When the value of this field is present, the VPN Gateway will be used for IPsec-encrypted Cloud Interconnect; all Egress or Ingress traffic for this VPN Gateway interface will go through the specified interconnect attachment resource.
-          # Not currently available in all Interconnect locations.
-      "ipAddress": "A String", # [Output Only] The external IP address for this VPN gateway interface.
+      "id": 42, # [Output Only] Numeric identifier for this VPN interface associated with the VPN gateway.
+      "interconnectAttachment": "A String", # URL of the VLAN attachment (interconnectAttachment) resource for this VPN gateway interface. When the value of this field is present, the VPN gateway is used for IPsec-encrypted Cloud Interconnect; all egress or ingress traffic for this VPN gateway interface goes through the specified VLAN attachment resource.
+          # Not currently available publicly.
+      "ipAddress": "A String", # [Output Only] IP address for this VPN interface associated with the VPN gateway. The IP address could be either a regional external IP address or a regional internal IP address. The two IP addresses for a VPN gateway must be all regional external or regional internal IP addresses. There cannot be a mix of regional external IP addresses and regional internal IP addresses. For IPsec-encrypted Cloud Interconnect, the IP addresses for both interfaces could either be regional internal IP addresses or regional external IP addresses. For regular (non IPsec-encrypted Cloud Interconnect) HA VPN tunnels, the IP address must be a regional external IP address.
     },
   ],
 }</pre>
@@ -398,12 +398,12 @@
   &quot;network&quot;: &quot;A String&quot;, # URL of the network to which this VPN gateway is attached. Provided by the client when the VPN gateway is created.
   &quot;region&quot;: &quot;A String&quot;, # [Output Only] URL of the region where the VPN gateway resides.
   &quot;selfLink&quot;: &quot;A String&quot;, # [Output Only] Server-defined URL for the resource.
-  &quot;vpnInterfaces&quot;: [ # A list of interfaces on this VPN gateway.
+  &quot;vpnInterfaces&quot;: [ # The list of VPN interfaces associated with this VPN gateway.
     { # A VPN gateway interface.
-      &quot;id&quot;: 42, # The numeric ID of this VPN gateway interface.
-      &quot;interconnectAttachment&quot;: &quot;A String&quot;, # URL of the interconnect attachment resource. When the value of this field is present, the VPN Gateway will be used for IPsec-encrypted Cloud Interconnect; all Egress or Ingress traffic for this VPN Gateway interface will go through the specified interconnect attachment resource.
-          # Not currently available in all Interconnect locations.
-      &quot;ipAddress&quot;: &quot;A String&quot;, # [Output Only] The external IP address for this VPN gateway interface.
+      &quot;id&quot;: 42, # [Output Only] Numeric identifier for this VPN interface associated with the VPN gateway.
+      &quot;interconnectAttachment&quot;: &quot;A String&quot;, # URL of the VLAN attachment (interconnectAttachment) resource for this VPN gateway interface. When the value of this field is present, the VPN gateway is used for IPsec-encrypted Cloud Interconnect; all egress or ingress traffic for this VPN gateway interface goes through the specified VLAN attachment resource.
+          # Not currently available publicly.
+      &quot;ipAddress&quot;: &quot;A String&quot;, # [Output Only] IP address for this VPN interface associated with the VPN gateway. The IP address could be either a regional external IP address or a regional internal IP address. The two IP addresses for a VPN gateway must be all regional external or regional internal IP addresses. There cannot be a mix of regional external IP addresses and regional internal IP addresses. For IPsec-encrypted Cloud Interconnect, the IP addresses for both interfaces could either be regional internal IP addresses or regional external IP addresses. For regular (non IPsec-encrypted Cloud Interconnect) HA VPN tunnels, the IP address must be a regional external IP address.
     },
   ],
 }
@@ -524,12 +524,12 @@
       &quot;network&quot;: &quot;A String&quot;, # URL of the network to which this VPN gateway is attached. Provided by the client when the VPN gateway is created.
       &quot;region&quot;: &quot;A String&quot;, # [Output Only] URL of the region where the VPN gateway resides.
       &quot;selfLink&quot;: &quot;A String&quot;, # [Output Only] Server-defined URL for the resource.
-      &quot;vpnInterfaces&quot;: [ # A list of interfaces on this VPN gateway.
+      &quot;vpnInterfaces&quot;: [ # The list of VPN interfaces associated with this VPN gateway.
         { # A VPN gateway interface.
-          &quot;id&quot;: 42, # The numeric ID of this VPN gateway interface.
-          &quot;interconnectAttachment&quot;: &quot;A String&quot;, # URL of the interconnect attachment resource. When the value of this field is present, the VPN Gateway will be used for IPsec-encrypted Cloud Interconnect; all Egress or Ingress traffic for this VPN Gateway interface will go through the specified interconnect attachment resource.
-              # Not currently available in all Interconnect locations.
-          &quot;ipAddress&quot;: &quot;A String&quot;, # [Output Only] The external IP address for this VPN gateway interface.
+          &quot;id&quot;: 42, # [Output Only] Numeric identifier for this VPN interface associated with the VPN gateway.
+          &quot;interconnectAttachment&quot;: &quot;A String&quot;, # URL of the VLAN attachment (interconnectAttachment) resource for this VPN gateway interface. When the value of this field is present, the VPN gateway is used for IPsec-encrypted Cloud Interconnect; all egress or ingress traffic for this VPN gateway interface goes through the specified VLAN attachment resource.
+              # Not currently available publicly.
+          &quot;ipAddress&quot;: &quot;A String&quot;, # [Output Only] IP address for this VPN interface associated with the VPN gateway. The IP address could be either a regional external IP address or a regional internal IP address. The two IP addresses for a VPN gateway must be all regional external or regional internal IP addresses. There cannot be a mix of regional external IP addresses and regional internal IP addresses. For IPsec-encrypted Cloud Interconnect, the IP addresses for both interfaces could either be regional internal IP addresses or regional external IP addresses. For regular (non IPsec-encrypted Cloud Interconnect) HA VPN tunnels, the IP address must be a regional external IP address.
         },
       ],
     },