YARN-7530. Refactored YARN service API project location.

            Contributed by Chandni Singh

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-services/hadoop-yarn-services-api/pom.xml

@@ -18,7 +18,7 @@
   <modelVersion>4.0.0</modelVersion>
   <parent>
     <groupId>org.apache.hadoop</groupId>
-    <artifactId>hadoop-yarn-applications</artifactId>
+    <artifactId>hadoop-yarn-services</artifactId>
     <version>3.1.1-SNAPSHOT</version>
   </parent>
   <artifactId>hadoop-yarn-services-api</artifactId>