Revert "Switch from Calculator to ExactCalculator"
Revert "Switch from Calculator to ExactCalculator"

Temporary revert to get TT builds in shape.

This reverts commit 846505dc35bb155c1c2cf54d407a946e8f732494.

Bug: 20745303
Change-Id: Id3455cba38b7aabaffa63c8531a6430f69897c6e

xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build