Created a new version of the database which used int instead of double to save the quantity. For now the upgrade seems to work.
Replaced the old Expense by the NewExpense
Enabled the method getAllExpensesFromCursor of the DBHelper. It seems to work.
Change the total used in the ExpenseList and ExpenseListTotal to int. Created a new class in Utils to manage the type convertions.
Set the remove icon of the action bar menu as shown always.
Uncomment the part which when the user addes a new expense, the app saves the data into the database. It seems to work.
Checked the modification of the expenses. It seems to work.