Disable Thunder's edge swipe to go back on Android

[hjiangsu]

Pull Request Description

This PR disables Thunder's edge swipe to go back gesture when Full Swipe Gestures is disabled. This does not affect Android's system navigation gestures. For iOS, the edge swipe to go back will always be enabled regardless of the setting toggle because that's the primary way to navigate back on iOS devices.

@micahmo if you could test this out on a physical device and let me know, that would be great! I tested it on an emulator and it seems to be working as expected there.

Issue Being Fixed

Issue Number: #1340

Screenshots / Recordings

Checklist

• [ ] Did you update CHANGELOG.md?
• [ ] Did you use localized strings where applicable?
• [ ] Did you add semanticLabels where applicable for accessibility?

[hjiangsu]

I'm still a bit unsure as to the cause of this bug because the page showed in the bug demo wasn't created with SwipeablePageRoute

Ahh yeah you're right - I wasn't able to reproduce that issue either. I think this is still a step in the right direction!