Fix surefire include pattern to only match generated/Sample*.java

Exclude src/samples/java/.../samples/Sample*.java from test execution
as those are standalone examples with main() method, not test classes.

Author: Changjian Wang

sdk/contentunderstanding/azure-ai-contentunderstanding/pom.xml

@@ -85,8 +85,9 @@
             <!-- Include standard test naming conventions -->
             <include>**/*Test.java</include>
             <include>**/*Tests.java</include>
-            <!-- Include Sample files as tests (they extend ContentUnderstandingClientTestBase) -->
-            <include>**/Sample*.java</include>
+            <!-- Include Sample files from generated directory only (they extend ContentUnderstandingClientTestBase) -->
+            <!-- Note: Exclude src/samples/java/*/samples/Sample*.java as those are standalone examples with main() -->
+            <include>**/generated/Sample*.java</include>
           </includes>
         </configuration>
       </plugin>