Rename lockdown admin configured networks API

* Renamed 'isLockdownAdminConfiguredNetworks'
  to 'hasLockdownAdminConfiguredNetworks'
* Renamed 'setLockdownAdminConfiguredNetworks'
  to 'setConfiguredNetworksLockdownState'

Bug: 148853269
Test: atest com.android.server.devicepolicy.DevicePolicyManagerTest
      atest com.android.cts.devicepolicy.MixedDeviceOwnerTest#testAdminConfiguredNetworks
      atest com.android.cts.devicepolicy.OrgOwnedProfileOwnerTest#testAdminConfiguredNetworks

Change-Id: I6bef862b4ef7e5a7997378efcff08477da9de6dc