Replace isTetheringWithSoftApConfig flag with B SDK check am: a10437f133 am: d2d93b35cb

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/3543708

Change-Id: Id554516ce91a48d5030fefab532b4ed5a6d57db5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>