Fix ConcurrentModificationException

ConcurrentModificationException could be happened during iterating if
parts are added newly.

Test: Select several images on Gallery app and attach them to a message
via Sharing

Signed-off-by: Taesu Lee <taesu82.lee@samsung.com>
Change-Id: Idb96239ef2c05a08fc0727797b97739aa89f12a4
diff --git a/src/com/android/messaging/ui/conversation/ComposeMessageView.java b/src/com/android/messaging/ui/conversation/ComposeMessageView.java
index 0f36e9a..c35927e 100644
--- a/src/com/android/messaging/ui/conversation/ComposeMessageView.java
+++ b/src/com/android/messaging/ui/conversation/ComposeMessageView.java
@@ -72,6 +72,7 @@
 import com.android.messaging.util.UiUtils;
 import com.android.messaging.util.UriUtil;
 
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 
@@ -683,7 +684,8 @@
         final boolean hasWorkingDraft = hasMessageText || hasSubject ||
                 mBinding.getData().hasAttachments();
 
-        final List<MessagePartData> attachments = draftMessageData.getReadOnlyAttachments();
+        final List<MessagePartData> attachments =
+                new ArrayList<MessagePartData>(draftMessageData.getReadOnlyAttachments());
         if (draftMessageData.getIsMms()) { // MMS case
             if (draftMessageData.hasAttachments()) {
                 if (hasAttachmentsChanged) {