Make data RAT icon test pass

Change merged in from aosp (I0428ba1749bdb884d210f1ff02cdf86b376a0ca8)
had a test written that was failing because the CL only updated the
status bar icon, not qs icon.

This is my attempt to make the code work as it seemed to be intended.

Test: runtest -x \
packages/SystemUI/tests/src/com/android/systemui/statusbar/policy/NetworkControllerDataTest.java \
-m testAlwaysShowDataRatIcon

Change-Id: I4fe11c2e866cbb1f7784e4ed109671a957ffdf36