DO NOT MERGE: Don't delete source file when a move opration is canceled

DNM becuase Code has moved in master.

Symptom:
A source file is deleted even if a move operation is cancled

Root cause:
MoveJob doesn't check whether a move operation is canceled or not
after copying file

Solution:
Add cancel condition check before deleting a source file

Bug: 30240042
Author: Shiotani Kouji <kouji.x.shiotani@sonymobile.com>
Change-Id: Ie68e5d96304a125c07d46a2fd5e4c9d84903d1e7

packages/DocumentsUI/src/com/android/documentsui/services/MoveJob.java

@@ -117,7 +117,9 @@ final class MoveJob extends CopyJob {
         byteCopyDocument(src, dest);
 
         // Remove the source document.
-        deleteDocument(src, srcParent);
+        if(!isCanceled()) {
+            deleteDocument(src, srcParent);
+        }
     }
 
     @Override