Revert "CTS: Add testConnectivityConstraintExecutes_withMobile to knownfailures"

This reverts commit 27c55e229b24fa7a3e620dccd29a3e1b8bda23b2.

Change-Id: I32d0f9094cf06905484e060f7fc2270c43273280
diff --git a/tests/expectations/knownfailures.txt b/tests/expectations/knownfailures.txt
index 07ef7fa..754e38a 100644
--- a/tests/expectations/knownfailures.txt
+++ b/tests/expectations/knownfailures.txt
@@ -104,13 +104,6 @@
   bug: 18091590
 },
 {
-  description: "Test is too flaky on some devices",
-  names: [
-    "android.jobscheduler.cts.ConnectivityConstraintTest#testConnectivityConstraintExecutes_withMobile"
-  ],
-  bug: 21262226
-},
-{
   description: "these tests require a good test scene, so they fail if run in random conditions",
   names: [
     "android.hardware.camera2.cts.AllocationTest#testBlackWhite",