[Refactor] Specify gradle plugins declaratively in example.

[panmari]

As opposed to declaratively. This is necessary to run with new java/gradle versions. See https://docs.flutter.dev/release/breaking-changes/flutter-gradle-plugin-apply. Jointly bumping version numbers for gradle and related for easier in a new flutter installation.

Tested by successfully compiling/installing example app on Android.

[chipweinberger]

you can just delete all the files and run this

cd ./example                                                                  
flutter config --enable-android 
flutter create .
flutter run

this way we are up to date with the latest recommendation

[panmari]

Done, the biggest difference was the additional move to kotlin.

[chipweinberger]

you have extra linux changes here

[chipweinberger]

Also, perhaps we should just delete all these files and change the docs to look like this:

[ekuleshov]

Also, perhaps we should just delete all these files and change the docs ...

@chipweinberger but what about Android manifest settings for bluetooth in the example app?

[panmari]

Rebased and removed linux changes. I feel it's easier to keep the boilerplate code to allow easily running the example. Outside of big moves, like the gradle declaritive style I point out in the description, updates won't be needed.

[chipweinberger]

Also, perhaps we should just delete all these files and change the docs ...

@chipweinberger but what about Android manifest settings for bluetooth in the example app?

good point. maybe we could just leave those files.