Revert "[netstack] Use optional field for the gateway in RouteTableEntry"
This reverts commit a39843a1ac9db29314069bcf382ec25802ed7c9f.
Reason for revert: the FIDL change breaks the Chromium prebuilts which blocks the garnet roller.
Original change's description:
> [netstack] Use optional field for the gateway in RouteTableEntry
>
> This changes the FIDL RouteTableEntry field for the gateway to an optional
> field and adds code to handle this properly.
>
> This broke recently when we moved to IP Addresses implemented as a union in
> FIDL. Before that we used a struct that had an enum NetAddressFamily that
> supports "UNSPECIFIED".
>
> This also fixes a couple of nits in ifconfig.
>
> NET-2059 #done
>
> Test: CQ and manual tests creating/deleting/showing routes
> Change-Id: Iceed3a4260a0143e9f4bfdc42ad88ba70fa98294
TBR=stijlist@google.com,tamird@google.com,eyalsoha@google.com,ckuiper@google.com
Change-Id: I32a9f53144a30683ba9925fbb8a78ce121cd097e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
6 files changed
