title: How to go to initialRoute with react-navigation when exiting a child stack navigator inside a drawer?
body: <p>I build an app with react-native, expo and react-navigation. I have a main drawer navigator who has in it 2 other stack navigator. One stack navigator have 2 pages; <code>Products</code> and Product. When I click on one product in the <code>Products</code> page, it goes into the <code>Product</code> page. Ben if I click on another link in my drawer navigator, I would like that the Products page's stack navigator would return to it's initialRoute when leaving the stack navigator.</p>
  
  <p>I tried to set the initialState for when I exit the stack navigator, it render the initialState when I click on the navigator link in my drawer navigator, but it doesn't work when I'm in the child page and exit the navigator. When I click again on <code>Products</code> in my drawer, instead of navigate to the <code>Products</code> page, it stayed on <code>Product</code>.</p>
  
  <p>I can create statics links in my drawer navigator and use <code>this.props.navigation.navigate</code> to always go to <code>this.props.navigation.navigate('Products')</code>, but it will be the last thing I want. I would really love that my drawer navigator stays dynamic with what I pass to it.</p>
  
  <p>I tried to <code>this.props.navigation.navigate</code> when the <code>componentWillUnmount</code>lifecycle goes on, but it didn't work.</p>
  
  <p>How can I do this?</p>
  
  <p>Thank you for your help!</p>