Default to 'All media' bucket for items from the rail.

This should give people a better multi-send experience when they want to
add more media.

src/org/thoughtcrime/securesms/ConversationActivity.java

@@ -2193,7 +2193,7 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
 
     @Override
     public void onQuickAttachment(Uri uri, String mimeType, String bucketId, long dateTaken, int width, int height) {
-      Media media = new Media(uri, mimeType, dateTaken, width, height, Optional.fromNullable(bucketId), Optional.absent());
+      Media media = new Media(uri, mimeType, dateTaken, width, height, Optional.of(Media.ALL_MEDIA_BUCKET_ID), Optional.absent());
       startActivityForResult(MediaSendActivity.getIntent(ConversationActivity.this, Collections.singletonList(media), recipient, composeText.getTextTrimmed(), sendButton.getSelectedTransport()), MEDIA_SENDER);
     }
   }

src/org/thoughtcrime/securesms/mediasend/Media.java

@@ -12,6 +12,8 @@ import org.whispersystems.libsignal.util.guava.Optional;
  */
 public class Media implements Parcelable {
 
+  public static final String ALL_MEDIA_BUCKET_ID = "org.thoughtcrime.securesms.ALL_MEDIA";
+
   private final Uri    uri;
   private final String mimeType;
   private final long   date;

src/org/thoughtcrime/securesms/mediasend/MediaRepository.java

@@ -31,8 +31,6 @@ import java.util.Map;
  */
 class MediaRepository {
 
-  private static final String ALL_MEDIA_BUCKET_ID = "org.thoughtcrime.securesms.ALL_MEDIA";
-
   /**
    * Retrieves a list of folders that contain media.
    */
@@ -80,7 +78,7 @@ class MediaRepository {
         allMediaCount += cameraFolder.getCount();
       }
 
-      mediaFolders.add(0, new MediaFolder(allMediaThumbnail, context.getString(R.string.MediaRepository_all_media), allMediaCount, ALL_MEDIA_BUCKET_ID, MediaFolder.FolderType.NORMAL));
+      mediaFolders.add(0, new MediaFolder(allMediaThumbnail, context.getString(R.string.MediaRepository_all_media), allMediaCount, Media.ALL_MEDIA_BUCKET_ID, MediaFolder.FolderType.NORMAL));
     }
 
     if (cameraFolder != null) {
@@ -150,7 +148,7 @@ class MediaRepository {
     String[]    projection    = Build.VERSION.SDK_INT >= 16 ? new String[] { Images.Media._ID, Images.Media.MIME_TYPE, Images.Media.DATE_TAKEN, Images.Media.WIDTH, Images.Media.HEIGHT }
                                                             : new String[] { Images.Media._ID, Images.Media.MIME_TYPE, Images.Media.DATE_TAKEN };
 
-    if (ALL_MEDIA_BUCKET_ID.equals(bucketId)) {
+    if (Media.ALL_MEDIA_BUCKET_ID.equals(bucketId)) {
       selection     = Images.Media.DATA + " NOT NULL";
       selectionArgs = null;
     }

src/org/thoughtcrime/securesms/mediasend/MediaSendViewModel.java

@@ -113,7 +113,7 @@ class MediaSendViewModel extends ViewModel {
     String candidate = media.get(0).getBucketId().get();
     for (int i = 1; i < media.size(); i++) {
       if (!Util.equals(candidate, media.get(i).getBucketId().orNull())) {
-        return Optional.absent();
+        return Optional.of(Media.ALL_MEDIA_BUCKET_ID);
       }
     }