Due to the wrong order of operations, the conversion
from RSSI to ASU was returning bad results. Fix the
equation so that the ASU is correctly calculated.
Bug: 126199198
Test: (force device to GSM) - atest CellInfoTest
verified on aosp_taimen
Change-Id: Iaeb9a2a6d8efb5b39fc1f81e8d2969694cc06422