fix custom coordinator duty (#11641)

diff --git a/integration-tests/docker/environment-configs/common-custom-coordinator-duties b/integration-tests/docker/environment-configs/common-custom-coordinator-duties
index 5f8c042..e6bddd6 100644
--- a/integration-tests/docker/environment-configs/common-custom-coordinator-duties
+++ b/integration-tests/docker/environment-configs/common-custom-coordinator-duties
@@ -74,7 +74,8 @@
 druid_indexer_task_ignoreTimestampSpecForDruidInputSource=true
 
 #Testing kill supervisor custom coordinator duty
-druid.coordinator.dutyGroups=["cleanupMetadata"]
-druid.coordinator.cleanupMetadata.duties=["killSupervisors"]
-druid.coordinator.cleanupMetadata.duty.killSupervisors.retainDuration=PT0M
-druid.coordinator.cleanupMetadata.period=PT10S
\ No newline at end of file
+druid_coordinator_kill_supervisor_on=false
+druid_coordinator_dutyGroups=["cleanupMetadata"]
+druid_coordinator_cleanupMetadata_duties=["killSupervisors"]
+druid_coordinator_cleanupMetadata_duty_killSupervisors_retainDuration=PT0M
+druid_coordinator_cleanupMetadata_period=PT10S
\ No newline at end of file
diff --git a/services/src/main/java/org/apache/druid/cli/CliCoordinator.java b/services/src/main/java/org/apache/druid/cli/CliCoordinator.java
index 4853c19..08f7a86 100644
--- a/services/src/main/java/org/apache/druid/cli/CliCoordinator.java
+++ b/services/src/main/java/org/apache/druid/cli/CliCoordinator.java
@@ -435,7 +435,7 @@
           if (Strings.isNullOrEmpty(props.getProperty(groupPeriodPropKey))) {
             throw new IAE("Run period for coordinator custom duty group must be set for group %s", coordinatorCustomDutyGroupName);
           }
-          Duration groupPeriod = jsonMapper.readValue(props.getProperty(groupPeriodPropKey), Duration.class);
+          Duration groupPeriod = new Duration(props.getProperty(groupPeriodPropKey));
           coordinatorCustomDutyGroups.add(new CoordinatorCustomDutyGroup(coordinatorCustomDutyGroupName, groupPeriod, coordinatorCustomDuties));
         }
         return new CoordinatorCustomDutyGroups(coordinatorCustomDutyGroups);