[improvement][launcher]Set system property s2.test in junit tests in order to facilitate conditional breakpoints.

launchers/standalone/pom.xml

@@ -83,6 +83,12 @@
             <artifactId>junit</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.junit-pioneer</groupId>
+            <artifactId>junit-pioneer</artifactId>
+            <version>1.6.0</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>