How to ignore uppercase and Lowercase in Firebase search

I have a method to return a Firebase user list as a result of a Firebase search SearchView (onQueryTextChange()).

However the method is case sensitive, I wanted to ignore this but so far I don't know how. For example, if you search for k and K, the results are different when they should be the same.

 public void pesquisaUsuario(String texto){
    listaUsuarios.clear();
    if (texto.length() > 0 ){
        Query query = usuariosF.orderByChild("nome")
                .startAt(texto)
                .endAt(texto + "\uf8ff");
        query.addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                for (DataSnapshot ds : dataSnapshot.getChildren()){
                    listaUsuarios.add(ds.getValue(Usuario.class));
                }
                adapterPesquisa.notifyDataSetChanged();
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });
    }
}