Always set interface down in object destruction
We would like to reason about our interfaces as being up
when they are configured and ready for use, and down otherwise.
This helps when switching modes. For example, when setting up a SoftAP,
you can expect that the interface starts in a down state, and
transitions to up when hostapd is ready for business. Note that we
cannot do this after firmware reload, because this may cause driver
de-initialization (see c#6 in b/31205821).
Bug: 31337216
Test: Integration tests pass
Change-Id: I03a71ea623e29ef9b023d97afc81cf836ebfb1ff
9 files changed