bug: Physical Back button exits app instead of going back in the nav

[anthonytietjen]

Type: bug

Ionic Version: 2.x

Platform: android 5.1 webview

Steps to reproduce issue:

1. ionic start myApp sidemenu --v2 --ts
2. ionic run android --device --livereload
3. Tap Menu Icon
4. Select "Lists"
5. Tap a list item to push a new ListPage onto the nav stack
6. Tap your device's physical Back button

Results:
The app exits and you are brought to the Android launch screen

Expected Results:
The ListPage would be popped off of the nav stack just like if you had tapped the software back button at the top left of the app.

[brandyscarney]

Thank you for the issue, we have this on our roadmap to finish around beta.4. There is an issue for it here: #5419

Please take a look at our roadmap for other features and fixes:
https://docs.google.com/document/d/1Qlc5X2eJyOB0izkFlH7KJ5BmMi0MeXUZRHJHt3hS6Wo/edit?usp=sharing