Merge "Schedule IMS -> CS redial notification to happen on main thread" into sc-dev am: a0d82996

                                         new SilentRedialParam(mLastDialString, cause, dialArgs),

                                         null);

        if (ar != null) {

            // There is a race condition that can happen in some cases:

            // (Main thread) dial start

            // (Binder Thread) onCallSessionFailed

            // (Binder Thread) schedule a redial for CS on the main thread

            // (Main Thread) dial finish

            // (Main Thread) schedule to associate ImsPhoneConnection with

            //               GsmConnection on the main thread

            // If scheduling the CS redial occurs before the command to schedule the

            // ImsPhoneConnection to be  associated with the GsmConnection, the CS redial will occur

            // before GsmConnection has had callbacks to ImsPhone correctly updated. This will cause

            // Callbacks back to GsmCdmaPhone to never be set up correctly and we will lose track of

            // the instance.

            // Instead, schedule this redial to happen on the main thread, so that we know dial has

            // finished before scheduling a redial:

            // (Main thread) dial start

            // (Binder Thread) onCallSessionFailed -> move notify registrants to main thread

            // (Main Thread) dial finish

            // (Main Thread) schedule on main thread to associate ImsPhoneConnection with

            //               GsmConnection

            // (Main Thread) schedule a redial for CS

            mContext.getMainExecutor().execute(() -> {

                logd("initiateSilentRedial: notifying registrants, isEmergency=" + isEmergency

                        + ", eccCategory=" + eccCategory);

                mSilentRedialRegistrants.notifyRegistrants(ar);

            });

        }

    }