Add more fields to METADATA proto am: 499dd08a65 am: c0b289c0cf

Original change: https://android-review.googlesource.com/c/platform/tools/external_updater/+/3392274

Change-Id: I1428f1a3a8aae6e95f631cf82de5a79af2737d8f
Signed-off-by: Automerger Merge Worker <[email protected]>
diff --git a/metadata.proto b/metadata.proto
index 47d0b16..09f7f8f 100644
--- a/metadata.proto
+++ b/metadata.proto
@@ -43,6 +43,7 @@
 
 enum DirectoryType {
   PACKAGE = 1;
+  GROUP = 2;
   GOOGLE_INTERNAL = 4;
 }
 
@@ -79,6 +80,7 @@
 
 message Identifier {
   optional string type = 1;
+  optional string omission_reason = 2;
   optional string value = 3;
   optional string version = 4;
   optional bool primary_source = 6;