[ICD]Retrigger subscription immediately when subscription stuck in idle status

Author: yunhanw-google

src/app/ReadClient.cpp

@@ -486,11 +486,14 @@ void ReadClient::OnActiveModeNotification()
 {
     // This function just tries to complete the deferred resubscription logic in `OnLivenessTimeoutCallback`.
     VerifyOrDie(mpImEngine->InActiveReadClientList(this));
-    // If we are not in InactiveICDSubscription state, that means the liveness timeout has not been reached. Simply do nothing.
-    VerifyOrReturn(IsInactiveICDSubscription());
+    // If we are in InactiveICDSubscription state, it means the liveness timeout has been reached. 
+    // If we are in Idle state, it means subscription stuck in initialized state, and device cannot be reached
+    // If we are not in the above, simply do nothing.
+    // If we are in the above, we should trigger immediate resubscription.
+    VerifyOrReturn(IsInactiveICDSubscription() || IsIdle());
 
-    // When we reach here, the subscription definitely exceeded the liveness timeout. Just continue the unfinished resubscription
-    // logic in `OnLivenessTimeoutCallback`.
+    mNumRetries = 0;
+    CancelResubscribeTimer();
     TriggerResubscriptionForLivenessTimeout(CHIP_ERROR_TIMEOUT);
 }