Fixes failing tests

Author: MaggieKimani1

test/Microsoft.OpenApi.Tests/Models/OpenApiExampleTests.SerializeAdvancedExampleAsV3JsonWorks_produceTerseOutput=False.verified.txt

@@ -8,7 +8,7 @@
           {
             "href": "http://example.com/1",
             "rel": "sampleRel1",
-            "bytes": "AQID",
+            "bytes": "\"AQID\"",
             "binary": "Ñ😻😑♮Í☛oƞ♑😲☇éNjžŁ♻😟¥a´Ī♃ƠąøƩ"
           }
         ]

test/Microsoft.OpenApi.Tests/Models/OpenApiExampleTests.SerializeAdvancedExampleAsV3JsonWorks_produceTerseOutput=True.verified.txt

@@ -1 +1 @@
-{"value":{"versions":[{"status":"Status1","id":"v1","links":[{"href":"http://example.com/1","rel":"sampleRel1","bytes":"AQID","binary":"Ñ😻😑♮Í☛oƞ♑😲☇éNjžŁ♻😟¥a´Ī♃ƠąøƩ"}]},{"status":"Status2","id":"v2","links":[{"href":"http://example.com/2","rel":"sampleRel2"}]}]}}
+{"value":{"versions":[{"status":"Status1","id":"v1","links":[{"href":"http://example.com/1","rel":"sampleRel1","bytes":"\"AQID\"","binary":"Ñ😻😑♮Í☛oƞ♑😲☇éNjžŁ♻😟¥a´Ī♃ƠąøƩ"}]},{"status":"Status2","id":"v2","links":[{"href":"http://example.com/2","rel":"sampleRel2"}]}]}}

test/Microsoft.OpenApi.Tests/Models/OpenApiExampleTests.SerializeReferencedExampleAsV3JsonWithoutReferenceWorks_produceTerseOutput=False.verified.txt

@@ -22,6 +22,6 @@
         ]
       }
     ],
-    "aDate": "2022-12-12"
+    "aDate": "\"2022-12-12\""
   }
 }

test/Microsoft.OpenApi.Tests/Models/OpenApiExampleTests.SerializeReferencedExampleAsV3JsonWithoutReferenceWorks_produceTerseOutput=True.verified.txt

@@ -1 +1 @@
-{"value":{"versions":[{"status":"Status1","id":"v1","links":[{"href":"http://example.com/1","rel":"sampleRel1"}]},{"status":"Status2","id":"v2","links":[{"href":"http://example.com/2","rel":"sampleRel2"}]}],"aDate":"2022-12-12"}}
+{"value":{"versions":[{"status":"Status1","id":"v1","links":[{"href":"http://example.com/1","rel":"sampleRel1"}]},{"status":"Status2","id":"v2","links":[{"href":"http://example.com/2","rel":"sampleRel2"}]}],"aDate":"\"2022-12-12\""}}

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

@@ -1,10 +1,11 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license. 
 
 using System;
 using System.Globalization;
 using System.IO;
 using System.Text;
+using System.Text.Json;
 using System.Text.Json.Nodes;
 using System.Threading.Tasks;
 using Microsoft.OpenApi.Any;
@@ -36,8 +37,8 @@ public class OpenApiExampleTests
                             {
                                 ["href"] = "http://example.com/1",
                                 ["rel"] = "sampleRel1",
-                                ["bytes"] = Convert.ToBase64String(new byte[] { 1, 2, 3 }),
-                                ["binary"] = Convert.ToBase64String(Encoding.UTF8.GetBytes("Ñ😻😑♮Í☛oƞ♑😲☇éNjžŁ♻😟¥a´Ī♃ƠąøƩ"))
+                                ["bytes"] = JsonSerializer.Serialize(new byte[] { 1, 2, 3 }),
+                                ["binary"] = Encoding.UTF8.GetString(Encoding.UTF8.GetBytes("Ñ😻😑♮Í☛oƞ♑😲☇éNjžŁ♻😟¥a´Ī♃ƠąøƩ"))
                             }
                         }
                     },
@@ -96,7 +97,8 @@ public class OpenApiExampleTests
                             }
                         }
                     }
-                }
+                },
+                ["aDate"] = JsonSerializer.Serialize(DateTime.Parse("12/12/2022 00:00:00").ToString("yyyy-MM-dd"))
             })
         };