K2GO-443 fix(app): unique add-ons notification id (review)

Notification id 8 is also ForgejoSeedService and CloneShareService; an add-ons download and a forgejo
seed can be foreground at once, so give the add-ons service a free id (11).

Author: luisguzman-adfa

controller/app/src/main/java/org/appdevforall/k2go/addons/presentation/AddonsDownloadService.java

@@ -27,7 +27,7 @@
 public final class AddonsDownloadService extends ContentDownloadServiceBase {
 
     private static final String CHANNEL_ID = "code_addons_download_channel";
-    private static final int NOTIFICATION_ID = 8;
+    private static final int NOTIFICATION_ID = 11;   // distinct: 8 is ForgejoSeedService / CloneShareService (may run concurrently)
 
     public static final String ACTION_START = "org.appdevforall.k2go.CODE_ADDONS_DOWNLOAD_START";
     public static final String ACTION_PAUSE = "org.appdevforall.k2go.CODE_ADDONS_DOWNLOAD_PAUSE";