We cannot test using WifiNetworkSpecifier, because the matching
behaviour for null WifiNetworkSpecifier changed between Q and R.
Replace WifiNetworkSpecifier with MatchAllNetworkSpecifier and
TelephonyNetworkSpecifier that behave the same in both Q and R
to verify.
Bug: 154451660
Test: atest CtsNetTestCasesLatestSdk:android.net.cts.NetworkRequestTest
on aosp and internal build
Change-Id: I14e2a5e629051e243f3b892b608cb1c6195cd8ed
6f63ef0e47