Clear a previous entity before showing an entity.

Tets: go/vtslab-schedule-dev
Bug: 125021352
Change-Id: I1ac0a0f61394066f07ff34b29bbf689c1fff0f1b
diff --git a/gae/frontend/src/app/app.component.ts b/gae/frontend/src/app/app.component.ts
index 68b7e6d..1a2ef06 100644
--- a/gae/frontend/src/app/app.component.ts
+++ b/gae/frontend/src/app/app.component.ts
@@ -41,6 +41,7 @@
     appService.closeSideNavEmitter.subscribe(() => {this.sideNavOpened = false});
     appService.showDetailsEmitter.subscribe(
       (entity) => {
+        this.selectedEntity.length = 0;
         if (entity) {
           let self = this;
           Object.keys(entity).forEach(function(value){