Use NotificationChannelCompat utilities (#5781)

app/src/main/java/eu/kanade/tachiyomi/util/system/NotificationExtensions.kt

@@ -0,0 +1,38 @@
+package eu.kanade.tachiyomi.util.system
+
+import androidx.core.app.NotificationChannelCompat
+import androidx.core.app.NotificationChannelGroupCompat
+
+/**
+ * Helper method to build a notification channel group.
+ *
+ * @param channelId the channel id.
+ * @param block the function that will execute inside the builder.
+ * @return a notification channel group to be displayed or updated.
+ */
+fun buildNotificationChannelGroup(
+    channelId: String,
+    block: (NotificationChannelGroupCompat.Builder.() -> Unit)
+): NotificationChannelGroupCompat {
+    val builder = NotificationChannelGroupCompat.Builder(channelId)
+    builder.block()
+    return builder.build()
+}
+
+/**
+ * Helper method to build a notification channel.
+ *
+ * @param channelId the channel id.
+ * @param channelImportance the channel importance.
+ * @param block the function that will execute inside the builder.
+ * @return a notification channel to be displayed or updated.
+ */
+fun buildNotificationChannel(
+    channelId: String,
+    channelImportance: Int,
+    block: (NotificationChannelCompat.Builder.() -> Unit)
+): NotificationChannelCompat {
+    val builder = NotificationChannelCompat.Builder(channelId, channelImportance)
+    builder.block()
+    return builder.build()
+}