Fix ConnectivityManagerTest#testFactoryReset flaky

Listen SoftAp callback to make sure soft ap is disabled
before start hotspot.

Bug: 277856014
Test: atest ConnectivityManagerTest#testFactoryReset
(cherry picked from https://android-review.googlesource.com/q/commit:5fab2d6c17c4ecdd6673e882f53f29d2136a23b0)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:846032e9455640b534a57ab0175c81d951b35fdf)
Merged-In: I95050be703b7c97da7a14541ac74718fdcbd7f13
Change-Id: I95050be703b7c97da7a14541ac74718fdcbd7f13
1 file changed