Fix notification timestamp to use original send time (#1112)

When notifications were delayed (e.g., due to lack of internet), Android
notifications showed the current time instead of the original message
timestamp. Added setWhen() and setShowWhen() to NotificationCompat.Builder.

app/src/main/java/io/heckel/ntfy/msg/NotificationService.kt

@@ -90,6 +90,8 @@ class NotificationService(val context: Context) {
             .setSmallIcon(R.drawable.ic_notification)
             .setColor(Colors.notificationIcon(context))
             .setContentTitle(title)
+            .setWhen(notification.timestamp * 1000) // Set timestamp (convert seconds to millis)
+            .setShowWhen(true)
             .setOnlyAlertOnce(true) // Do not vibrate or play sound if already showing (updates!)
             .setAutoCancel(true) // Cancel when notification is clicked
         setStyleAndText(builder, subscription, notification) // Preview picture or big text style

fastlane/metadata/android/en-US/changelog/NEXT.txt

@@ -5,3 +5,4 @@ Features:
 
 Bug fixes + maintenance:
 * Fix crash when URL scheme is missing in default server (#1582, ntfy-android#158, thanks to @hard-zero1 for reporting)
+* Fix notification timestamp to use original send time instead of receive time (#1112, thanks to @voruti for reporting)