Merge "Validate underlying network when VPN switches to unvalidated" into main am: 4b1ce0f3

         * <p>This variable controls the retry delay, and is reset when the VPN pass network

         * validation.

         */

        private int mValidationFailRetryCount = 0;

        @VisibleForTesting(visibility = VisibleForTesting.Visibility.PRIVATE)

        int mValidationFailRetryCount = 0;

        /**

         * The number of attempts since the last successful connection.

                // Skip other invalid status if the scheduled recovery exists.

                if (mScheduledHandleDataStallFuture != null) return;

                // Trigger network validation on the underlying network to possibly cause system

                // switch default network or try recover if the current default network is broken.

                //

                // For the same underlying network, the first validation result should clarify if

                // it's caused by broken underlying network. So only perform underlying network

                // re-evaluation after first validation failure to prevent extra network resource

                // costs on sending probes.

                if (mValidationFailRetryCount == 0) {

                    mConnectivityManager.reportNetworkConnectivity(

                            mActiveNetwork, false /* hasConnectivity */);

                }

                if (mValidationFailRetryCount < MAX_MOBIKE_RECOVERY_ATTEMPT) {

                    Log.d(TAG, "Validation failed");