Before the Target would sometimes be garbage collected before being called with the loaded channel icon, since Picasso holds weak references to targets. This meant that sometimes a new streams notification would not be shown, because the lambda that should have shown it had already been garbage collected.
It never kicked in since we are never returning a retry() Result, but always either success() or failure() (see createWork() function). Also, there is already a default (exponential backoff starting from 30 seconds), so no need to override it.
Removed some non-translatable strings and just hardcoded them in the code, like it's being done for other string separators. This also deduplicates some code by using Localization.
Used some Kotlin feature to reduce code.
Do not open the setting for a specific notification channel (Settings.ACTION_CHANNEL_NOTIFICATION_SETTINGS), but the settings for all notifications by the app (Settings.ACTION_APP_NOTIFICATION_SETTINGS)