Drop Support for Android 4.4

[andreban]

While the project generated by Bubblewrap supports Android 4.4 (Kitkat) and above, Chrome has moved to support Android 5.0 (Lollipop) and above.

Even though support for TWAs across browsers has increased, those devices are less likely to have a compatible one installed. Additionally, when the Custom Tabs / browser fallback are used user reviews are generally worse when the WebView fallback is used.

As a caveat, the Android WebView doesn't support all the features from the web platform, which means apps may not work as intended in this fallback.

There are two possible approaches to improve this:

1. Make the WebView fallback the default
2. Update Bubblewrap to generate projects targeting Android 5.0 (Lollipop) and above.

[andreban]

CC @jdecked for thoughts

[PEConn]

Android KitKat support was finished in Chrome 81. TWAs were launched with Chrome 72 with a few big features (splash screens, notification delegation) coming in Chrome 75.

So it's possible to get a functioning TWA on Android KitKat with Chrome - but it will be out of date.

[jdecked]

We did get a few positive + grateful app store reviews after launching with Android 4.4 support. It'd be great if we could figure out a way to keep it, since it does seem to serve //some// appetite.

@PEConn when you say "out of date", what in particular is missing?

@andreban what's supported in WebView but not in Custom Tabs? Would be good if we could set WebView as the default fallback only for Android <5.0.

[PEConn]

Some TWA specific features won't be supported - for example Location Delegation or Play Billing, as well as any bug fixes made in the last year or so. Also, any new web APIs or bug fixes (including security fixes) in Chrome that have been made over the last year.

For the last point though, the user will be using the out of date Chrome anyway, so I don't think you'll be making the situation any worse.