I've tried adding margin to my BottomSheetDialogFragment, however it doesn't do anything for the margins.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_margin="16dp">
    <TextView
        android:id="@+id/alertdialog_fragmail_newmessage"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Test 1"
        android:textStyle="bold"
        android:padding="16dp"
        android:textColor="@color/colorBlackFont"
        android:layout_alignParentTop="true"
        android:gravity="center_vertical"
        android:drawablePadding="16dp"/>
  //More Textviews
</RelativeLayout>
Edit:_________________________________________________________________
I've tried changing the XML to the answer below, however it's still not creating margins for my bottomsheetdialogfragment.
The code for the Bottom sheet dialog fragment class:
public class FragMailMoreDialog extends BottomSheetDialogFragment {
    private static final String TAG = "FragMailMoreDialog";
    private Context mContext;
    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mContext = getContext();
    }
    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater,
                             @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.alertdialog_layout_fragmailmore, container, false);
        ButterKnife.bind(this, view);
        return view;
    }
}
The code to inflating the bottomsheet:
private void inflateMoreDialog(){
        FragMailMoreDialog moreDialog = new FragMailMoreDialog();
        if (getFragmentManager() != null) {
            moreDialog.show(getFragmentManager(), "FRAGMAIL_MORE_DIALOG");
        }
    }
