Remove mysterious test logic

Remove mysterious test logic that probably
isn't used.

It was added in frameworks/base commit
a27421a306c49fbe9b3823b30f7ab1cd58b28854 to
GsmServiceStateTracker.

The logic can be removed because the
system property is used for testing, and
even if it were, controlling behavior based
on whether the realtime clock value is odd
or even is strange.

Test:
atest FrameworksTelephonyTests:com.android.internal.telephony.NitzStateMachineTest

Test: build / boot / see above
Bug: 63743683
Change-Id: I51de9a81eaaa49974dcc94dffcd22c1f417728fa