Cardinal interpolation error

-Seems like for the big numbers, d3 is interpolating
 data badly and it is creating loops in the chart.
 So quick fix is to switch to linear interpolation
 as default.
-Other interpolation can be set with settings.

Change-Id: I82c1514dce6034b3cbc7f95682356a08301482b7
Fixes-bug: #1295537
Merge "Cardinal interpolation error"