[CrOSCellular] Fix eSIM install failure when already connecting.

This CL fixes issue with eSIM profile installation failing
when network is already in connecting or connected state
after enable. This can occur if Shill attempts to autoconnect
immediately after enable.

Fixed: 1189758
Change-Id: Ib698609157d8395a8ba1acc4f0430dcdd65a3497
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2773636


Commit-Queue: Azeem Arshad <azeemarshad@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#864887}