Math add api adds a `.0` on integer increments

[abose]

When we use math add to increment an integer, a decimal point .0 is added, which is not expected.

Eg. Increment(0) will return 1.0 instead of 1 in db document.

// initial db entry: {  totalDownloads: 273  }
await db.mathAdd(TABLE, documentId, {
        totalDownloads: 1
    });
// initial db entry: {  totalDownloads: 274.0 }