workaround leaf-list via uses bug in BGP route-map (PR sonic-net#21078)

There is a bug in libyang when attempting to use table `BGP_PEER_GROUP_AF`
and likely `BGP_NEIGHBOR_AF` in respect to `route_map_in` and `route_map_out`.

The issue is with the use of `leaf-list` specifically when it is pulled in
via a `uses` clause `bgpcmn:sonic-bgp-cmn-af`.

The error message resembles that of if a child is specified that isn't
recognized at all:
```
All Keys are not parsed in BGP_PEER_GROUP_AF
dict_keys(['default|PEERS|ipv4_unicast'])
exceptionList:["'route_map_in'"]
```

Moving the leaf-list to the parent rather than being imported
through the `uses` clause works around this issue.

Signed-off-by: Brad House (@bradh352)

Author: bradh352

src/sonic-yang-models/yang-models/sonic-bgp-common.yang

@@ -382,22 +382,6 @@ module sonic-bgp-common {
             description "Interval after which connection will get re-established";
         }
 
-        leaf-list route_map_in {
-            type leafref {
-                path "/rmap:sonic-route-map/rmap:ROUTE_MAP_SET/rmap:ROUTE_MAP_SET_LIST/rmap:name";
-            }
-            description "Route-map filter for incoming routes";
-            max-elements 1;
-        }
-
-        leaf-list route_map_out {
-            type leafref {
-                path "/rmap:sonic-route-map/rmap:ROUTE_MAP_SET/rmap:ROUTE_MAP_SET_LIST/rmap:name";
-            }
-            description "Route-map filter for outgoing routes";
-            max-elements 1;
-        }
-
         leaf soft_reconfiguration_in {
             type boolean;
             description "Inbound soft reconfiguration";

src/sonic-yang-models/yang-models/sonic-bgp-neighbor.yang

@@ -28,6 +28,10 @@ module sonic-bgp-neighbor {
     //    prefix vlan;
     //}
 
+    import sonic-route-map {
+        prefix rmap;
+    }
+
     import sonic-bgp-global {
         prefix bgpg;
     }
@@ -130,7 +134,26 @@ module sonic-bgp-neighbor {
                     }
                     description "BGP Neighbor, it will be neighbor address or interface name";
                 }
+
                 uses bgpcmn:sonic-bgp-cmn-af;
+
+                // These should logically be in sonic-bgp-cmn-af, however due to a libyang2 bug when including
+                // a leaf-list entry, there are validation failures.
+                leaf-list route_map_in {
+                    type leafref {
+                        path "/rmap:sonic-route-map/rmap:ROUTE_MAP_SET/rmap:ROUTE_MAP_SET_LIST/rmap:name";
+                    }
+                    description "Route-map filter for incoming routes";
+                    max-elements 1;
+                }
+
+                leaf-list route_map_out {
+                    type leafref {
+                        path "/rmap:sonic-route-map/rmap:ROUTE_MAP_SET/rmap:ROUTE_MAP_SET_LIST/rmap:name";
+                    }
+                    description "Route-map filter for outgoing routes";
+                    max-elements 1;
+                }
             }
         }
     }

src/sonic-yang-models/yang-models/sonic-bgp-peergroup.yang

@@ -15,6 +15,10 @@ module sonic-bgp-peergroup {
         prefix bgpg;
     }
 
+    import sonic-route-map {
+        prefix rmap;
+    }
+
     organization
         "SONiC";
 
@@ -68,6 +72,24 @@ module sonic-bgp-peergroup {
                 }
 
                 uses bgpcmn:sonic-bgp-cmn-af;
+
+                // These should logically be in sonic-bgp-cmn-af, however due to a libyang2 bug when including
+                // a leaf-list entry, there are validation failures.
+                leaf-list route_map_in {
+                    type leafref {
+                        path "/rmap:sonic-route-map/rmap:ROUTE_MAP_SET/rmap:ROUTE_MAP_SET_LIST/rmap:name";
+                    }
+                    description "Route-map filter for incoming routes";
+                    max-elements 1;
+                }
+
+                leaf-list route_map_out {
+                    type leafref {
+                        path "/rmap:sonic-route-map/rmap:ROUTE_MAP_SET/rmap:ROUTE_MAP_SET_LIST/rmap:name";
+                    }
+                    description "Route-map filter for outgoing routes";
+                    max-elements 1;
+                }
             }
         }