Update tests and public API interface

Author: MaggieKimani1

test/Microsoft.OpenApi.Tests/Models/OpenApiParameterTests.SerializeParameterWithSchemaTypeObjectAsV2JsonWorksAsync_produceTerseOutput=False.verified.txt

@@ -3,5 +3,11 @@
   "name": "name1",
   "description": "description1",
   "required": true,
-  "type": "string"
+  "type": "string",
+  "x-examples": {
+    "test": {
+      "summary": "summary3",
+      "description": "description3"
+    }
+  }
 }

test/Microsoft.OpenApi.Tests/Models/OpenApiParameterTests.SerializeParameterWithSchemaTypeObjectAsV2JsonWorksAsync_produceTerseOutput=True.verified.txt

@@ -1 +1 @@
-{"in":"header","name":"name1","description":"description1","required":true,"type":"string"}
+{"in":"header","name":"name1","description":"description1","required":true,"type":"string","x-examples":{"test":{"summary":"summary3","description":"description3"}}}

test/Microsoft.OpenApi.Tests/Models/OpenApiParameterTests.cs

@@ -272,7 +272,13 @@ public void SerializeAdvancedParameterAsV2JsonWorks()
                   "name": "name1",
                   "description": "description1",
                   "required": true,
-                  "format": "double"
+                  "format": "double",
+                  "x-examples": {
+                    "test": {
+                      "summary": "summary3",
+                      "description": "description3"
+                    }
+                  }
                 }
                 """;
 

test/Microsoft.OpenApi.Tests/PublicApi/PublicApi.approved.txt

@@ -1486,6 +1486,7 @@ namespace Microsoft.OpenApi.Writers
         void WriteRaw(string value);
         void WriteStartArray();
         void WriteStartObject();
+        void WriteV2Examples(Microsoft.OpenApi.Writers.IOpenApiWriter writer, Microsoft.OpenApi.Models.OpenApiExample example, Microsoft.OpenApi.OpenApiSpecVersion version);
         void WriteValue(bool value);
         void WriteValue(decimal value);
         void WriteValue(int value);
@@ -1547,6 +1548,7 @@ namespace Microsoft.OpenApi.Writers
         public abstract void WriteRaw(string value);
         public abstract void WriteStartArray();
         public abstract void WriteStartObject();
+        public void WriteV2Examples(Microsoft.OpenApi.Writers.IOpenApiWriter writer, Microsoft.OpenApi.Models.OpenApiExample example, Microsoft.OpenApi.OpenApiSpecVersion version) { }
         public virtual void WriteValue(bool value) { }
         public virtual void WriteValue(System.DateTime value) { }
         public virtual void WriteValue(System.DateTimeOffset value) { }