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
diff --git a/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java b/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
index f0ad3f1..4451a88 100644
--- a/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
+++ b/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
@@ -2591,6 +2591,7 @@
             // prevent the race condition between airplane mode enabled and the followed
             // up wifi tethering enabled.
             tetherEventCallback.expectNoTetheringActive();
+            tetherUtils.expectSoftApDisabled();
 
             // start wifi tethering
             tetherUtils.startWifiTethering(tetherEventCallback);