[roll] Roll fuchsia [usb-cdc-ecm] Track comm interface and validate MAC descriptor

In composite USB configurations, the CDC-ECM communications interface
number can be non-zero. Previously, control transfers targeting the
communications interface (such as packet filter and multicast filter
configuration) hardcoded 0 as the interface index, causing control
requests to stall on composite devices. Track the communications
interface number and pass it as the wIndex parameter.

Additionally, reject 0 as an invalid MAC descriptor string index in the
Ethernet functional descriptor to avoid treating missing MAC descriptors
as valid (string descriptor index 0 is reserved for USB Language IDs).
Add unit test coverage for non-zero interface numbers and invalid MAC
descriptors.

Test: fx test usb-cdc-ecm-unittest
Original-Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1849018
Original-Original-Revision: 68d1272ef7780dae52a4993196261adec5216414
GitOrigin-RevId: be159c36585495e0395081c7370d2da1a6ce723a
Change-Id: I70a26b6857a7b932e550ec457cb164aae11f30b3
Reviewed-on: https://fuchsia-review.googlesource.com/c/integration/+/1859639
Cr-Commit-Position: refs/heads/main@{#204084}