Use "date sent" as timestamp for push, "date received" for SMS.

The "sent time" is not reliable on SMS messages.  This switches
to using "sent time" by default for push messages, but "received
time" for SMS messages.

src/org/thoughtcrime/securesms/ConversationItem.java

@@ -266,7 +266,10 @@ public class ConversationItem extends LinearLayout {
     } else if (messageRecord.isPending()) {
       dateText.setText(" ··· ");
     } else {
-      final long timestamp = messageRecord.getDateSent();
+      final long timestamp;
+
+      if (messageRecord.isPush()) timestamp = messageRecord.getDateSent();
+      else                        timestamp = messageRecord.getDateReceived();
 
       dateText.setText(DateUtils.getBetterRelativeTimeSpanString(getContext(), timestamp));
     }

src/org/thoughtcrime/securesms/database/ThreadDatabase.java

@@ -23,15 +23,14 @@ import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteOpenHelper;
 import android.util.Log;
 
-import org.whispersystems.textsecure.crypto.InvalidMessageException;
-import org.whispersystems.textsecure.crypto.MasterCipher;
-import org.whispersystems.textsecure.crypto.MasterSecret;
 import org.thoughtcrime.securesms.database.model.DisplayRecord;
 import org.thoughtcrime.securesms.database.model.MessageRecord;
 import org.thoughtcrime.securesms.database.model.ThreadRecord;
 import org.thoughtcrime.securesms.recipients.Recipient;
 import org.thoughtcrime.securesms.recipients.RecipientFactory;
 import org.thoughtcrime.securesms.recipients.Recipients;
+import org.whispersystems.textsecure.crypto.InvalidMessageException;
+import org.whispersystems.textsecure.crypto.MasterCipher;
 import org.whispersystems.textsecure.util.Util;
 
 import java.util.Arrays;
@@ -379,11 +378,16 @@ public class ThreadDatabase extends Database {
     MmsSmsDatabase.Reader reader = null;
 
     try {
-      reader               = mmsSmsDatabase.readerFor(mmsSmsDatabase.getConversationSnippet(threadId));
-      MessageRecord record = null;
+      reader = mmsSmsDatabase.readerFor(mmsSmsDatabase.getConversationSnippet(threadId));
+      MessageRecord record;
 
       if (reader != null && (record = reader.getNext()) != null) {
-        updateThread(threadId, count, record.getBody().getBody(), record.getDateReceived(), record.getType());
+        final long timestamp;
+
+        if (record.isPush()) timestamp = record.getDateSent();
+        else                 timestamp = record.getDateReceived();
+
+        updateThread(threadId, count, record.getBody().getBody(), timestamp, record.getType());
       } else {
         deleteThread(threadId);
       }