Revert "Don't serialize exceptions"

This reverts commit dbfc731.

Author: arteam

server/src/main/java/org/elasticsearch/action/admin/cluster/snapshots/get/GetSnapshotsResponse.java

@@ -55,6 +55,8 @@ public GetSnapshotsResponse(
 
     public GetSnapshotsResponse(StreamInput in) throws IOException {
         this.snapshots = in.readCollectionAsImmutableList(SnapshotInfo::readFrom);
+        // TODO Skip when we have V9 in TransportVersions
+        in.readMap(StreamInput::readException);
         this.next = in.readOptionalString();
         this.total = in.readVInt();
         this.remaining = in.readVInt();
@@ -85,6 +87,8 @@ public int remaining() {
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         out.writeCollection(snapshots);
+        // TODO Skip when we have V9 in TransportVersions
+        out.writeMap(Map.of(), StreamOutput::writeException);
         out.writeOptionalString(next);
         out.writeVInt(total);
         out.writeVInt(remaining);