Add missing call to get window handle to sample (Azure#39460)

Author: billwert

sdk/identity/azure-identity-broker-samples/src/samples/java/com/azure/identity/broker/JavaDocCodeSnippets.java

@@ -42,7 +42,9 @@ public void configureCredentialForWindows() {
 
     public void configureCredentialForDefaultAccount() {
         // BEGIN: com.azure.identity.broker.interactivebrowserbrokercredentialbuilder.useinteractivebrowserbroker.defaultaccount
+        long windowHandle = getWindowHandle(); // Samples below
         InteractiveBrowserCredential cred = new InteractiveBrowserBrokerCredentialBuilder()
+            .setWindowHandle(windowHandle)
             .useDefaultBrokerAccount()
             .build();
         // END: com.azure.identity.broker.interactivebrowserbrokercredentialbuilder.useinteractivebrowserbroker.defaultaccount

sdk/identity/azure-identity-broker/README.md

@@ -94,7 +94,9 @@ InteractiveBrowserCredential cred = new InteractiveBrowserBrokerCredentialBuilde
 When this option is enabled, the credential will attempt to silently use the default broker account. If using the default account fails, the credential will fall back to interactive authentication.
 
 ```java com.azure.identity.broker.interactivebrowserbrokercredentialbuilder.useinteractivebrowserbroker.defaultaccount
+long windowHandle = getWindowHandle(); // Samples below
 InteractiveBrowserCredential cred = new InteractiveBrowserBrokerCredentialBuilder()
+    .setWindowHandle(windowHandle)
     .useDefaultBrokerAccount()
     .build();
 ```