This update provides the meat for the image download feature
within the Core.   Minimal testing was done with the CLI as the
adapters have not implemented this feature so far.

Change-Id: I771340876d9aa1f368642cd44a433ced3df52673
diff --git a/protos/device.proto b/protos/device.proto
index 16186fa..902a58c 100644
--- a/protos/device.proto
+++ b/protos/device.proto
@@ -110,6 +110,7 @@
         DOWNLOAD_STARTED = 3;
         DOWNLOAD_FAILED = 4;
         DOWNLOAD_UNSUPPORTED = 5;
+        DOWNLOAD_CANCELLED = 6;
     }
 
     enum ImageDownloadFailureReason {
@@ -123,9 +124,10 @@
     enum ImageActivateState {
         IMAGE_UNKNOWN = 0;
         IMAGE_INACTIVE = 1;
-        IMAGE_ACTIVATE = 2;
+        IMAGE_ACTIVATING = 2;
         IMAGE_ACTIVE = 3;
-        IMAGE_REVERT = 4;
+        IMAGE_REVERTING = 4;
+        IMAGE_REVERTED = 5;
     }
 
     // Device Identifier