Remove the DisabledState from NsdService

In order to increase the line coverage for the Connectivity
module, remove the DisabledState from NsdService which is
uselss for a while.

Bug: 234315786
Test: atest FrameworksNetTests CtsNetTestCases \
      ConnectivityCoverageTest
Change-Id: I29c7ef608d97037084b25daa70ad5829f474e20a
2 files changed