[@capacitor/share] "Can't share while sharing is in progress" when sharing to the same app on Android

## Bug Report

### Plugin(s)

@capacitor/share

### Capacitor Version

```
💊 Capacitor Doctor 💊

Latest Dependencies:

@capacitor/cli: 7.4.3
@capacitor/core: 7.4.3
@capacitor/android: 7.4.3
@capacitor/ios: 7.4.3

Installed Dependencies:

@capacitor/ios: not installed
@capacitor/cli: 7.4.3
@capacitor/core: 7.4.3
@capacitor/android: 7.4.3

[success] Android looking great! 👌
```

### Platform(s)

Android

### Current Behavior

In my app I have both outgoing + incoming share functionality. When I try to share anything to the same app, the plugin's Android implementation becomes stuck in some "in-progress" state, and subsequent share calls immediately fail with error:
```
Can't share while sharing is in progress
```

### Expected Behavior

All subsequent shares from the app into same app work OK.

### Code Reproduction

I've prepared reproduction repo - please check out https://github.com/dmitry-salnikov/capacitor-share-plugin-bug-reproduction

### Other Technical Details

Android only, everything works OK on iOS.

## Additional Context

#### The problem

- Android tries to launch `MainActivity` with the `ACTION_SEND intent`.
- Because `launchMode="singleTask"`, Android doesn't create a new activity instance. Instead, it reuses the existing task and brings it to the front.
- Since the activity never finishes (it's the same instance), `activityResult()` is never called.
- This way, `isPresenting` flag isn't reset, and all subsequent calls to `share()` would throw error `Can't share while sharing is in progress`.

#### The solution
Handle incoming share intent in SharePlugin's code to reset `isPresenting` flag and resolve plugin call, e.g.:

```java
@Override
protected void handleOnNewIntent(Intent intent) {
if (isPresenting && intent != null && Intent.ACTION_SEND.equals(intent.getAction())) {
PluginCall call = bridge.getSavedCall("activityResult");
if (call != null) {
call.resolve(new JSObject().put("activityType", ""));
}
isPresenting = false;
}
}
```