function updateNotifiedStatus(sheet, notifiedValues, i, beginningRow) {
  // Update notification status.
  notifiedValues[i][0] = 'NOTIFIED';
  sheet.getRange(i + beginningRow, COLUMN_NUMBER.NOTIFY).setValue('NOTIFIED');
}
Sets the notification status to NOTIFIED for employees
who have received a notification email.

@param {Object} sheet Current Spreadsheet.
@param {Object} notifiedValues Array of notified values.
@param {Integer} i Current status in the for loop.
@parma {Integer} beginningRow Row where iterations began.