[TC] Update format on timesystem change

Update the format when the timesystem changes.

Fixes https://github.com/nasa/openmct/issues/1585

platform/features/conductor/core/src/ui/TimeConductorController.js

@@ -406,6 +406,7 @@ define(
             var config = this.getConfig(timeSystem, clock);
 
             this.$scope.timeSystemModel.selected = timeSystem;
+            this.$scope.timeSystemModel.format = timeSystem.timeFormat;
 
             if (clock === undefined) {
                 this.timeAPI.timeSystem(timeSystem, config.bounds);