[Thread] unify synchronous controller API for testing am: 62eac0132d

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2995697

Change-Id: I4f0e0a2390473cd70085ab336605af8811d6e8c6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>