Add android.net.IpPrefix#contains()

This was originally to avoid RuntimeException in RouteInfo#matches():
    When an IPv6 prefix with a length greater than the max permitted
    for IPv4 is matched against an Inet4Address, the call to
    NetworkUtils throws RuntimeException.

Change-Id: I92e2bd19a4e7d656cf682fd27678da07e211850d
6 files changed