Log additional details around group sends.

app/src/main/java/org/thoughtcrime/securesms/messages/GroupSendUtil.java

@@ -160,6 +160,8 @@ public final class GroupSendUtil {
                                                      @Nullable CancelationSignal cancelationSignal)
       throws IOException, UntrustedIdentityException
   {
+    Log.i(TAG, "Starting group send. GroupId: " + (groupId != null ? groupId.toString() : "none") + ", RelatedMessageId: " + (relatedMessageId != null ? relatedMessageId.toString() : "none") + ", Targets: " + allTargets.size() + ", RecipientUpdate: " + isRecipientUpdate + ", Operation: " + sendOperation.getClass().getSimpleName());
+
     Set<Recipient>  unregisteredTargets = allTargets.stream().filter(Recipient::isUnregistered).collect(Collectors.toSet());
     List<Recipient> registeredTargets   = allTargets.stream().filter(r -> !unregisteredTargets.contains(r)).collect(Collectors.toList());