Create view state files for `dashboard` and `search`

Release-Notes: skip
Google-Bug-Id: b/244279450
Change-Id: Iebb3b3cd6f0fa33d3e9ed46b1245890d376db466
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 7c362f5..0b396f0 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
@@ -253,12 +253,12 @@
     if (!value || value.view !== GerritView.SEARCH) return;
     const offset = isNaN(Number(value.offset)) ? 0 : Number(value.offset);
 
-    if (this.query !== value.query) {
+    if (this.query !== (value.query ?? '')) {
       this.selectedIndex = 0;
     }
 
     this.loading = true;
-    this.query = value.query;
+    this.query = value.query ?? '';
     this.offset = offset;
 
     // NOTE: This method may be called before attachment. Fire title-change