title: Google play Subscriptions Free trial
body: <p>Is there any way how to check if user've already used his free trial?</p>
  
  <p>When I query sub I got the next data:</p>
  
  <pre><code>[
      SkuDetails:{
          "productId":"...",
          "type":"subs",
          "price":"...",
          "price_amount_micros":0000,
          "price_currency_code":"USD",
          "subscriptionPeriod":"P1M",
          "freeTrialPeriod":"P1W1D",
          "title":"...",
          "description":"..."
      }
  ]
  </code></pre>
  
  <p>Will this field 
      "freeTrialPeriod":"P1W1D" disappear when a user uses his free trial?
  Or maybe there's some other way to know it?</p>
  
  <p>I need to show "free" instead of subscription price and then show actual price after user used his free trial </p>