Update git submodules

* Update plugins/download-commands from branch 'master'
  to 47b783ea75036664dd591d2d3f1bcd06b68cdd5e
  - Replace using refToId with Change.Id.fromRef
    
    This fixes an issue where refToId returned null for change edits,
    Change.Id.fromRef explicity adds change edit support,
    so swapping from using refToId() to Change.Id.fromRef
    fixes the issue. On the plus we're using a core method
    instead of duplicating things.
    
    Bug: Issue 12575
    Change-Id: Id4619348fc7498dab69b4d888f360097bd9e80e3
    

plugins/download-commands

diff --git a/plugins/download-commands b/plugins/download-commands
index e26ed31..47b783e 160000
--- a/plugins/download-commands
+++ b/plugins/download-commands
@@ -1 +1 @@
-Subproject commit e26ed31aaf070ff884e96b9a09d39c20437de6cb
+Subproject commit 47b783ea75036664dd591d2d3f1bcd06b68cdd5e