Fixed force_show_in_foreground parameter when set to false

[Jei]

This PR fixes a bug that prevents data notifications from being shown with the app closed or in background, when sending the force_show_in_foreground parameter as false.

Push notification test code:

<?php $url = 'https://fcm.googleapis.com/fcm/send';

	$fields = array (
			'to' => "<FCM TOKEN>",
			'data' => array(
				"test1" => "value1",
				"test2" => "value2",
				"timestamp"=>date('Y-m-d G:i:s'),
				"title" => "title",
				"message" => "message",
				"big_text"=>"big text even more text big text even more text big text even more text big text even more text big text even more text big text even more text big text even more text big text even more text big text even more text big text even more text big text even more text big text even more text big text even more text big text even more text ",
				"big_text_summary"=>"big_text_summary",
				"icon" => "http://via.placeholder.com/150x150",
				"image" => "http://via.placeholder.com/350x150",	// won't show the big_text
				"force_show_in_foreground"=> false,
				"color" => "#ff6600",
				"channelId" => "default"	// or a different channel
			)
	);

	$headers = array (
			'Authorization: key=<SERVER KEY>',
			'Content-Type: application/json'
	);

	$ch = curl_init ();
	curl_setopt ( $ch, CURLOPT_URL, $url );
	curl_setopt ( $ch, CURLOPT_POST, true );
	curl_setopt ( $ch, CURLOPT_HTTPHEADER, $headers );
	curl_setopt ( $ch, CURLOPT_RETURNTRANSFER, true );
	curl_setopt ( $ch, CURLOPT_POSTFIELDS, json_encode($fields));

	$result = curl_exec ( $ch );
	echo $result."\n";
	curl_close ( $ch );
?>

[m1ga]

before:

• no notification when app is in background and force_show_in_foreground is set

after PR:

• notification is shown when app is in background and force_show_in_foreground is set

When app is in foreground it behaves as expected too

Ready to merge!