[FUI06] Stop using NetworkInfo in NetworkState from external callers

This is achieved by:
  1. Use legacy network type inside NetworkState to replace the
     needs of referencing NetworkInfo.getType().
  2. Let getAllNetworkState only return networks with isConnected()
     equals true. This allows callers such as NPMS or NSS does not
     have to reference to NetworkInfo.isConnected().

Test: atest FrameworksNetTests NetworkPolicyManagerServiceTest
Bug: 174123988
Change-Id: I1c4eb08d18ca973eb8f41d06258872eabc0006b8

tests/net/java/android/net/NetworkTemplateTest.kt

@@ -62,7 +62,6 @@ class NetworkTemplateTest {
     ): NetworkState {
         val info = mock(NetworkInfo::class.java)
         doReturn(type).`when`(info).type
-        doReturn(NetworkInfo.State.CONNECTED).`when`(info).state
         val lp = LinkProperties()
         val caps = NetworkCapabilities().apply {
             setCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED, false)