Describe the bug
When extending the navigation rail, the icons and labels jump to the right when extending, instead of smoothly extending out.

To switch channel run:

flutter channel master
flutter upgrade

Flutter doctor
Copy and paste the output of flutter doctor -v here

To Reproduce
Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior
The navigation rail smoothly extends, showing the extended content.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.