wifi: Use public APIs for RouteInfo.isIPv4Default

Bug: 145232020
Test: Connect to wifi networks
Test: Ensured that RouteInfo no longer shows up in the wifi-service
extenal hidden API dependency list.
Test: atest com.android.server.wifi

Change-Id: I1539adde5862c6cbdc3bfcbc25c00f072d6cf74f
2 files changed
tree: 72b59a9c8c4bfd3621dfe6a7ddd6e3141fb088e3
  1. apex/
  2. service/
  3. PREUPLOAD.cfg