Adding the null check to monitiring frequncy and fixing the servlet-api issue which is caused a compilation error

components/policy-mgt/org.wso2.carbon.policy.mgt.core/src/main/java/org/wso2/carbon/policy/mgt/core/util/PolicyManagerUtil.java

@@ -204,11 +204,13 @@ public class PolicyManagerUtil {
             tenantConfiguration = configMgtService.getConfiguration(GENERAL_CONFIG_RESOURCE_PATH);
             List<ConfigurationEntry> configuration = tenantConfiguration.getConfiguration();
 
+            if (configuration != null && !configuration.isEmpty()) {
                 for (ConfigurationEntry cEntry : configuration) {
                     if (cEntry.getName().equalsIgnoreCase(MONITORING_FREQUENCY)) {
                         monitoringFrequency = (int) cEntry.getValue();
                     }
                 }
+            }
 
         } catch (ConfigurationManagementException e) {
             log.error("Error while getting the configurations from registry.", e);

pom.xml

@@ -312,6 +312,10 @@
                         <groupId>commons-pool.wso2</groupId>
                         <artifactId>commons-pool</artifactId>
                     </exclusion>
+                    <exclusion>
+                        <groupId>javax.servlet</groupId>
+                        <artifactId>servlet-api</artifactId>
+                    </exclusion>
                 </exclusions>
             </dependency>
             <dependency>
@@ -386,6 +390,10 @@
                         <groupId>org.wso2.carbon.registry</groupId>
                         <artifactId>org.wso2.carbon.registry.extensions</artifactId>
                     </exclusion>
+                    <exclusion>
+                        <groupId>javax.servlet</groupId>
+                        <artifactId>servlet-api</artifactId>
+                    </exclusion>
                 </exclusions>
             </dependency>
             <!-- End of Governance dependencies -->
@@ -808,6 +816,10 @@
                         <groupId>org.wso2.carbon.registry</groupId>
                         <artifactId>org.wso2.carbon.registry.ws.client</artifactId>
                     </exclusion>
+                    <exclusion>
+                        <groupId>javax.servlet</groupId>
+                        <artifactId>servlet-api</artifactId>
+                    </exclusion>
                 </exclusions>
             </dependency>
             <dependency>