[ham] Fixed sleep recorder, returned value

[ham] Fixed sleep recorder, returned value

[Bug] there was missing conversion from numerical value from database to string value used in Web API

[Verification] TCT passrate 100% on wearable TW3.
Below code works when activity added manually to database.
var data = [];
date = new Date(), startTime = date.getTime(), endTime = date.setDate(date.getDate() + 1),
    query = {
        startTime: startTime/1000,
        endTime: endTime/1000,
        interval: 1440
    };
tizen.humanactivitymonitor.readRecorderData("SLEEP_MONITOR", query, (s) => console.log(data = s), (s) => console.log(s))

returns one of values of "ASLEEP", "AWAKE", or "UNKNOWN"

Change-Id: I86b6bead534638bafcb5abcb16512bb462c79374