feat(core): back button event on Android, closes #8142

[lucasfernog]

I've used https://github.com/ionic-team/capacitor-plugins/blob/main/app/android/src/main/java/com/capacitorjs/plugins/app/AppPlugin.java as a reference here, checking if there's a back button event handler with a default of webview's goBack implementation

[github-actions]

Package Changes Through bd3f5c2

There are 9 changes which include @tauri-apps/api with minor, tauri-cli with minor, tauri-utils with minor, tauri-runtime-wry with minor, tauri-runtime with minor, tauri with minor, tauri-bundler with minor, @tauri-apps/cli with minor, tauri-macros with patch

Planned Package Versions

The following package releases are the planned based on the context of changes in this pull request.

package	current	next
@tauri-apps/api	2.8.0	2.9.0
tauri-utils	2.7.0	2.8.0
tauri-bundler	2.6.1	2.7.0
tauri-runtime	2.8.0	2.9.0
tauri-runtime-wry	2.8.1	2.9.0
tauri-codegen	2.4.0	2.4.1
tauri-macros	2.4.0	2.4.1
tauri-plugin	2.4.0	2.4.1
tauri-build	2.4.1	2.4.2
tauri	2.8.5	2.9.0
@tauri-apps/cli	2.8.4	2.9.0
tauri-cli	2.8.4	2.9.0

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[lucasfernog]

the exit impl still needs to be tested

[lucasfernog]

I've removed the App::exit impl - after further testing, the existing API is working fine

[FabianLars]

If i register a callback it seems to work fine but if i don't register one, i get [TAURI] Couldn't find callback id ... errors when i use the back button.
Also it likely was because of my scuffed testing but i couldn't really make use of canGoBack: true since it just navigates in that case. Any tips how to test this?

p.s. i had to merge #14132 into my local clone of this branch for the listener to work.

[lucasfernog]

If i register a callback it seems to work fine but if i don't register one, i get [TAURI] Couldn't find callback id ... errors when i use the back button. Also it likely was because of my scuffed testing but i couldn't really make use of canGoBack: true since it just navigates in that case. Any tips how to test this?

p.s. i had to merge #14132 into my local clone of this branch for the listener to work.

ohh i didn't realize wry handled this.. i'll push an update