Use credential in samples (Azure#28708)

Author: heaths

sdk/template/Azure.Template/README.md

@@ -68,7 +68,7 @@ The `GetSecret` method retrieves a secret from the service.
 ```C# Snippet:Azure_Template_GetSecret
 string endpoint = "https://myvault.vault.azure.net";
 var credential = new DefaultAzureCredential();
-var client = new TemplateClient(endpoint, new DefaultAzureCredential());
+var client = new TemplateClient(endpoint, credential);
 
 SecretBundle secret = client.GetSecretValue("TestSecret");
 

sdk/template/Azure.Template/samples/Sample1.HelloWorldAsync.md

@@ -16,7 +16,7 @@ You can also get secrets asynchronously:
 ```C# Snippet:Azure_Template_GetSecretAsync
 string endpoint = "https://myvault.vault.azure.net";
 var credential = new DefaultAzureCredential();
-var client = new TemplateClient(endpoint, new DefaultAzureCredential());
+var client = new TemplateClient(endpoint, credential);
 
 SecretBundle secret = await client.GetSecretValueAsync("TestSecret");
 

sdk/template/Azure.Template/samples/Sample1_HelloWorld.md

@@ -16,7 +16,7 @@ You can create a client and get secrets synchronously:
 ```C# Snippet:Azure_Template_GetSecret
 string endpoint = "https://myvault.vault.azure.net";
 var credential = new DefaultAzureCredential();
-var client = new TemplateClient(endpoint, new DefaultAzureCredential());
+var client = new TemplateClient(endpoint, credential);
 
 SecretBundle secret = client.GetSecretValue("TestSecret");
 

sdk/template/Azure.Template/tests/Samples/Sample1_HelloWorld.cs

@@ -26,7 +26,7 @@ public void GettingASecret()
             string endpoint = TestEnvironment.KeyVaultUri;
             var credential = TestEnvironment.Credential;
 #endif
-            var client = new TemplateClient(endpoint, new DefaultAzureCredential());
+            var client = new TemplateClient(endpoint, credential);
 
             SecretBundle secret = client.GetSecretValue("TestSecret");
 

sdk/template/Azure.Template/tests/Samples/Sample1_HelloWorldAsync.cs

@@ -24,7 +24,7 @@ public async Task GettingASecretAsync()
             string endpoint = TestEnvironment.KeyVaultUri;
             var credential = TestEnvironment.Credential;
 #endif
-            var client = new TemplateClient(endpoint, new DefaultAzureCredential());
+            var client = new TemplateClient(endpoint, credential);
 
             SecretBundle secret = await client.GetSecretValueAsync("TestSecret");