Updating autorest readme link (Azure#21244)

Co-authored-by: Minnie Liu <peiliu@microsoft.com>

Author: minnieliu

sdk/communication/Azure.Communication.Identity/src/autorest.md

@@ -8,6 +8,6 @@ Run `dotnet msbuild /t:GenerateCode` to generate code.
 ``` yaml
 tag: package-2021-03-07
 require:
-    -  https://raw.githubusercontent.com/Azure/azure-rest-api-specs/bf081421869ccd31d9fd87084b07a1e246aee310/specification/communication/data-plane/Microsoft.CommunicationServicesIdentity/readme.md
+    -  https://raw.githubusercontent.com/Azure/azure-rest-api-specs/896d05e37dbb00712726620b8d679cc3c3be09fb/specification/communication/data-plane/Identity/readme.md
 payload-flattening-threshold: 3
 ```

sdk/communication/Azure.Communication.PhoneNumbers/src/autorest.md

@@ -9,7 +9,7 @@ Run `dotnet msbuild /t:GenerateCode` to generate code.
 public-clients: true
 tag: package-phonenumber-2021-03-07
 require:
-    -  https://raw.githubusercontent.com/Azure/azure-rest-api-specs/bf081421869ccd31d9fd87084b07a1e246aee310/specification/communication/data-plane/Microsoft.CommunicationServicesPhoneNumbers/readme.md
+    -  https://raw.githubusercontent.com/Azure/azure-rest-api-specs/896d05e37dbb00712726620b8d679cc3c3be09fb/specification/communication/data-plane/PhoneNumbers/readme.md
 title: Phone numbers
 payload-flattening-threshold: 3
 ```

sdk/communication/Azure.Communication.Sms/src/autorest.md

@@ -8,6 +8,6 @@ Run `dotnet msbuild /t:GenerateCode` to generate code.
 ``` yaml
 tag: package-sms-2021-03-07
 require:
-    -  https://raw.githubusercontent.com/Azure/azure-rest-api-specs/bf081421869ccd31d9fd87084b07a1e246aee310/specification/communication/data-plane/Microsoft.CommunicationServicesSms/readme.md
+    -  https://raw.githubusercontent.com/Azure/azure-rest-api-specs/896d05e37dbb00712726620b8d679cc3c3be09fb/specification/communication/data-plane/Sms/readme.md
 payload-flattening-threshold: 10
 ```