Fix issue in healthcheck API

Author: msm1992

components/apimgt/org.wso2.carbon.apimgt.gateway/src/main/java/org/wso2/carbon/apimgt/gateway/internal/DataHolder.java

@@ -235,7 +235,7 @@ public void markApisAsUnDeployedInTenant(String tenantDomain) {
 
     private void initializeTenantDeploymentStatusMap() {
         try {
-            List<String> tenants = GatewayUtils.getTenantsToBeDeployed();
+            Set<String> tenants = GatewayUtils.getTenantsToBeDeployed();
             tenantDeployStatus = tenants.stream().collect(Collectors.toMap(str -> str, str -> false));
         } catch (APIManagementException e) {
             log.error("Error while initializing tenant deployment status map", e);

components/apimgt/org.wso2.carbon.apimgt.gateway/src/main/java/org/wso2/carbon/apimgt/gateway/utils/GatewayUtils.java

@@ -1741,8 +1741,8 @@ public static String getEagerLoadingEnabledTenantsConfig() {
      *
      * @return List of eager loading enabled tenants
      */
-    public static List<String> getTenantsToBeDeployed() throws APIManagementException {
-        List<String> tenantsToBeDeployed = new ArrayList<>();
+    public static Set<String> getTenantsToBeDeployed() throws APIManagementException {
+        Set<String> tenantsToBeDeployed = new HashSet<>();
         tenantsToBeDeployed.add(APIConstants.SUPER_TENANT_DOMAIN);
 
         //Read eager loading config from carbon server config, and extract include and exclude tenant lists