Move automatic backups from /backup/automatic to /autobackup

Removes the need to try to create child folders, which simplifies things.

(cherry picked from commit f365b53a0fbfb6f4147c688416e101aee9bae7fc)

app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupCreator.kt

@@ -120,7 +120,6 @@ class BackupCreator(
                 if (isAutoBackup) {
                     // Get dir of file and create
                     val dir = UniFile.fromUri(context, uri)
-                        .createDirectory("automatic")
 
                     // Delete older backups
                     dir.listFiles { _, filename -> Backup.filenameRegex.matches(filename) }

domain/src/main/java/tachiyomi/domain/storage/service/StoragePreferences.kt

@@ -11,7 +11,7 @@ class StoragePreferences(
     fun baseStorageDirectory() = preferenceStore.getString("storage_dir", folderProvider.path())
 
     companion object {
-        const val BACKUP_DIR = "backup"
+        const val BACKUP_DIR = "autobackup"
         const val DOWNLOADS_DIR = "downloads"
     }
 }