AMBARI-25870: Upgrade Swagger to 1.6.2+ for avoiding NoSuchMethodError (#3649)

ambari-project/pom.xml

@@ -33,7 +33,7 @@
     <jetty.version>9.4.12.v20180830</jetty.version>
     <ldap-api.version>1.0.0</ldap-api.version>
     <checkstyle.version>8.9</checkstyle.version>
-    <swagger.version>1.5.19</swagger.version>
+    <swagger.version>1.6.8</swagger.version>
     <swagger.maven.plugin.version>3.1.5</swagger.maven.plugin.version>
     <slf4j.version>2.0.0</slf4j.version>
     <reload4j.version>1.2.22</reload4j.version>