[YANG] Enable Yang model for BGP_BBR config entry (#17622)

Why I did it
Enable Yang model for BGP_BBR config entry.

{
        "BGP_BBR": {
            "all": {
                "status": "enabled"/"disabled"
            }
        }
}
Work item tracking
Microsoft ADO (number only): 25988660
How I did it
Add yang model and ut for BGP_BBR.

How to verify it
Use GCU cmd to change bbr status.
Create following json patch: disable_bbr.json-patch

[
 {
  "op": "replace",
  "path": "/BGP_BBR/all/status",
  "value": "disabled"
 }
]
Run sudo config apply-patch ./disable_bbr.json-patch cmd on dut. Success.

src/sonic-yang-models/doc/Configuration.md

@@ -7,9 +7,12 @@ Table of Contents
    * [Introduction](#introduction)
    * [Configuration](#configuration)
    * [<strong>Config Load and Save</strong>](#config-load-and-save)
+
          * [Incremental Configuration](#incremental-configuration)
    * [<strong>Redis and Json Schema</strong>](#redis-and-json-schema)
+
          * [ACL and Mirroring](#acl-and-mirroring)
+         * [BGP BBR](#bgp-bbr)
          * [BGP Device Global](#bgp-device-global)
          * [BGP Sessions](#bgp-sessions)
          * [BUFFER_PG](#buffer_pg)
@@ -367,6 +370,18 @@ and migration plan
     }
 }
 ```
+### BGP BBR
+
+The **BGP_BBR** table contains device-level BBR state.
+```
+{
+        "BGP_BBR": {
+            "all": {
+                "status": "enabled"/"disabled"
+            }
+        }
+}
+```
 ### BGP Device Global
 
 The **BGP_DEVICE_GLOBAL** table contains device-level BGP global state.

src/sonic-yang-models/setup.py

@@ -85,6 +85,7 @@ setup(
     data_files=[
         ('yang-models', ['./yang-models/sonic-acl.yang',
                          './yang-models/sonic-auto_techsupport.yang',
+                         './yang-models/sonic-bgp-bbr.yang',
                          './yang-models/sonic-bgp-common.yang',
                          './yang-models/sonic-bgp-device-global.yang',
                          './yang-models/sonic-bgp-global.yang',

src/sonic-yang-models/tests/files/sample_config_db.json

@@ -1597,6 +1597,11 @@
                 "local_ip": "12.12.0.2"
             }
         },
+        "BGP_BBR": {
+            "all": {
+                "status": "enabled"
+            }
+        },
         "BGP_GLOBALS": {
             "default": {
                 "router_id": "5.5.5.5",

src/sonic-yang-models/tests/yang_model_tests/tests/bgp_bbr.json

@@ -0,0 +1,9 @@
+{
+    "BGP_BBR_TABLE": {
+        "desc": "BGP BBR Table"
+    },
+    "BGP_BBR_INVALID_STATUS": {
+        "desc": "Configure status key with invalid value",
+        "eStrKey": "InvalidValue"
+    }
+}

src/sonic-yang-models/tests/yang_model_tests/tests_config/bgp_bbr.json

@@ -0,0 +1,22 @@
+{
+    "BGP_BBR_TABLE": {
+        "sonic-bgp-bbr:sonic-bgp-bbr": {
+            "sonic-bgp-bbr:BGP_BBR": {
+                "all":
+                {
+                    "status": "enabled"
+                }
+            }
+        }
+    },
+    "BGP_BBR_INVALID_STATUS": {
+        "sonic-bgp-bbr:sonic-bgp-bbr": {
+            "sonic-bgp-bbr:BGP_BBR": {
+                "all":
+                {
+                    "status": "true"
+                }
+            }
+        }
+    }
+}

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

@@ -0,0 +1,41 @@
+module sonic-bgp-bbr {
+    namespace "http://github.com/sonic-net/sonic-bgp-bbr";
+    prefix bgpbbr;
+    yang-version 1.1;
+
+    import sonic-types {
+        prefix stypes;
+    }
+
+    organization
+        "SONiC";
+
+    contact
+        "SONiC";
+
+    description
+        "SONIC BGP BBR";
+
+    revision 2023-12-25 {
+        description
+            "Initial revision.";
+    }
+
+    container sonic-bgp-bbr {
+        container BGP_BBR {
+
+            description "BGP_BBR table part of config_db.json";
+
+            container all {
+                leaf status {
+                    type stypes:admin_mode;
+                    default enabled;
+                    description "bgp bbr status";
+                }
+            }
+            /* end of container all */
+        }
+        /* end of container BGP_BBR */
+    }
+    /* end of container sonic-bgp-bbr */
+}