title: Angular reset TransferState data on route change
body: <p>I'm using Angular with server-side rendering and TransferState to transfer http data from server to browser. Here is my code:</p>
  
  <pre class="lang-js prettyprint-override"><code>getProducts() {
      let products = this.tstate.get(PRODUCT_KEY, null as any);
      if (products) {
          return of(products);
      }
  
      return this.http.post&lt;any&gt;(config.baseUrl+ 'product', {}).pipe(map(
          data =&gt; {
              this.tstate.set(PRODUCT_KEY, data as any);
              return data;
          }
      ))
  }
  </code></pre>
  
  <p>In the first load, I get the data from http request. Then the state is initializing. After that, when the route changes, still transfer state keeps the data, so I can't send the request to get the data. Any idea how to reset transfer state in route changing?</p>