Make backup jobs cancelable.

app/src/main/java/org/thoughtcrime/securesms/database/AttachmentTable.kt

@@ -1068,6 +1068,23 @@ class AttachmentTable(
     }
   }
 
+  /**
+   * Updates the attachment (and all attachments that share the same data file) with a new length.
+   */
+  fun updateAttachmentLength(attachmentId: AttachmentId, length: Long) {
+    val dataFile = getDataFileInfo(attachmentId)
+    if (dataFile == null) {
+      Log.w(TAG, "[$attachmentId] Failed to find data file!")
+      return
+    }
+
+    writableDatabase
+      .update(TABLE_NAME)
+      .values(DATA_SIZE to length)
+      .where("$DATA_FILE = ?", dataFile.file.absolutePath)
+      .run()
+  }
+
   /**
    * When we find out about a new inbound attachment pointer, we insert a row for it that contains all the info we need to download it via [insertAttachmentWithData].
    * Later, we download the data for that pointer. Call this method once you have the data to associate it with the attachment. At this point, it is assumed
@@ -2804,7 +2821,10 @@ class AttachmentTable(
     FINISHED(3),
 
     /** It is impossible to upload this attachment. */
-    PERMANENT_FAILURE(4);
+    PERMANENT_FAILURE(4),
+
+    /** Upload failed, but in a way where it may be worth retrying later. */
+    TEMPORARY_FAILURE(5);
 
     companion object {
       fun deserialize(value: Int): ArchiveTransferState {