Properly check attachment size during media send.

Prevent users from trying to send videos that exceed the size limit.

Also, this commit properly populates height/width on media shared into
the app.

Fixes #8573

src/org/thoughtcrime/securesms/mediapreview/MediaPreviewViewModel.java

@@ -105,6 +105,7 @@ public class MediaPreviewViewModel extends ViewModel {
                      mediaRecord.getDate(),
                      mediaRecord.getAttachment().getWidth(),
                      mediaRecord.getAttachment().getHeight(),
+                     mediaRecord.getAttachment().getSize(),
                      Optional.absent(),
                      Optional.fromNullable(mediaRecord.getAttachment().getCaption()));
   }