Get rid of @override.

- Remove superfluous @override.
- Replace @override with override
- Get rid of empty overridden method in
  `polygerrit-ui/app/elements/shared/gr-editable-content/gr-editable-content.ts`

Change-Id: Ibcf63c0d1d22e64abd36323f371549e56eee7e23
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.ts
index fa3c9c6..50bbda9 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.ts
@@ -122,8 +122,7 @@
 
   reporting: ReportingService = appContext.reportingService;
 
-  /** @override */
-  connectedCallback() {
+  override connectedCallback() {
     super.connectedCallback();
     getPluginLoader()
       .awaitPluginsLoaded()
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view.ts
index 84bc1e2..9970dd5 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view.ts
@@ -118,8 +118,7 @@
     this.addEventListener('previous-page', () => this._handlePreviousPage());
   }
 
-  /** @override */
-  connectedCallback() {
+  override connectedCallback() {
     super.connectedCallback();
     this._loadPreferences();
   }
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list.ts b/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list.ts
index 3acb079..5c0bab8 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list.ts
@@ -166,16 +166,14 @@
     );
   }
 
-  /** @override */
-  ready() {
+  override ready() {
     super.ready();
     this.restApiService.getConfig().then(config => {
       this._config = config;
     });
   }
 
-  /** @override */
-  connectedCallback() {
+  override connectedCallback() {
     super.connectedCallback();
     getPluginLoader()
       .awaitPluginsLoaded()
@@ -185,7 +183,6 @@
       });
   }
 
-  /** @override */
   override disconnectedCallback() {
     this.cursor.unsetCursor();
     super.disconnectedCallback();
diff --git a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts
index 41a7598..c341dea 100644
--- a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts
@@ -124,8 +124,7 @@
     super();
   }
 
-  /** @override */
-  connectedCallback() {
+  override connectedCallback() {
     super.connectedCallback();
     this._loadPreferences();
     this.addEventListener('reload', () => this._reload(this.params));