Process one connection update request at a time per device am: da2a7e62 am: 35e848bc

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Bluetooth/+/3496758



Change-Id: I7b2842bb264b562da147c5b81414d5a27e259bc8
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>