Rename testPreferenceForUserNetworkUpDownForGivenPreference.

This method name is confusing because it is not a test, and
convention in this file is that only test methods are called
testXyz. Rename it to doTestXyz.

Bug: 143158421
Test: test-only change
Change-Id: Ief9742174a7fc9966ade29d9a32a13277ce747ac
1 file changed