Resolve #3423201 "Configuration mobile collapse of chathive"

Closes #3423201

config/schema/chathive.schema.yml

@@ -15,6 +15,8 @@ chathive.chathive.*:
       type: string
     description:
       type: string
+    browser_zoom:
+      type: boolean
     visibility:
       type: sequence
       label: 'Visibility Conditions'