UPSTREAM: iface-modem: sim swap check always refers to the active SIM

Since 503e886c02 the events on inactive SIMs don't trigger a full
modem reprobe, and the slot index check is fully unused.

(cherry picked from commit 4db5635f4414547909c585f1802a1105dd07dacc)

BUG=b:265671227
TEST=test issue scenario: suspend-resume without SIM inserted.

Change-Id: I164d0cd5b01019e87c86cf43c2254d29a938c95c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/modemmanager-next/+/4770631
Reviewed-by: Aleksander Morgado <aleksandermj@google.com>
Commit-Queue: Rukun Mao <rmao@google.com>
Tested-by: Rukun Mao <rmao@google.com>
3 files changed