Add a method to get All Defined Permissions of the AndroidManifest.xml file.

### Is there already an issue requesting this feature?

- [x] I have searched the [existing issues](https://github.com/baseflow/flutter-permission-handler/issues).

### Please select affected platform(s)

- [x] Android
- [ ] iOS
- [ ] Windows

### Use case

Currently Permission.values returns all permissions, if we had a getDefinedPermissions() that would return only the permissions i put on androidManifest.xml i coud loop the returned list to see if there is a permission that is not granted, and if there is i could just call list.request();

### Proposal

i once made something like this on native android
```Java
if (PermissionCheck.needToAsk(this)) {
PermissionCheck.ask(this);
return;
}

public class PermissionCheck {

private PermissionCheck() {

}

public static boolean needToAsk(Context context) {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
return false;
}
try {
PackageInfo packageInfo;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
packageInfo = context.getPackageManager().getPackageInfo(context.getPackageName(), PackageManager.PackageInfoFlags.of(PackageManager.GET_PERMISSIONS));
} else {
packageInfo = context.getPackageManager().getPackageInfo(context.getPackageName(), PackageManager.GET_PERMISSIONS);
}
String[] permissions = packageInfo.requestedPermissions;

for (String permission : permissions) {
if (isNotGranted(context, permission)) {
return true;
}
}

} catch (PackageManager.NameNotFoundException e) {
e.printStackTrace();
}
return false;
}

private static boolean isNotGranted(Context context, String permission) {
if (Build.VERSION.SDK_INT < 31 && (permission.contains("BLUETOOTH_SCAN") || permission.contains("BLUETOOTH_ADVERTISE") || permission.contains("BLUETOOTH_CONNECT"))) {
return false;
}
return ContextCompat.checkSelfPermission(context, permission) != PackageManager.PERMISSION_GRANTED;
}

public static void ask(Activity context) {
try {
PackageInfo packageInfo;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
packageInfo = context.getPackageManager().getPackageInfo(context.getPackageName(), PackageManager.PackageInfoFlags.of(PackageManager.GET_PERMISSIONS));
} else {
packageInfo = context.getPackageManager().getPackageInfo(context.getPackageName(), PackageManager.GET_PERMISSIONS);
}
String[] permissions = packageInfo.requestedPermissions;
List list = new ArrayList<>();
for (String permission : permissions) {
if (isNotGranted(context, permission)) {
list.add(permission);
}
}
if (list.isEmpty()) {
return;
}
String[] array = list.toArray(new String[0]);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
ActivityCompat.requestPermissions(context, array, 0);
}

} catch (PackageManager.NameNotFoundException e) {
MetodosEstaticos.toastException(e, context);
}
}
}
```

But i guess a getDefinedPermissions would be enough.

### Specific requirements or considerations

_No response_

### Additional information or context

_No response_

Start at the Permission.values API and trace the Android plugin path that reads AndroidManifest.xml; review how the existing permission list is exposed to Dart. Done means an Android-only getDefinedPermissions() result contains only manifest-declared permissions and can be iterated for subsequent permission checks.

Written by the indexing model from the issue text.