Merge "Add an Executor as a parameter of addOnSubscriptionsChangedListener"...

import android.content.Context;

import android.content.Intent;

import android.content.IntentFilter;

import android.os.Handler;

import android.os.Looper;

import android.telephony.PhoneStateListener;

import android.telephony.ServiceState;

    private final HeadsetService mHeadsetService;

    private final TelephonyManager mTelephonyManager;

    private final SubscriptionManager mSubscriptionManager;

    private final Handler mHandler;

    private ServiceState mServiceState;

        mSubscriptionManager = SubscriptionManager.from(mHeadsetService);

        Objects.requireNonNull(mSubscriptionManager, "TELEPHONY_SUBSCRIPTION_SERVICE is null");

        // Initialize subscription on the handler thread

        mOnSubscriptionsChangedListener = new HeadsetPhoneStateOnSubscriptionChangedListener(

                headsetService.getStateMachinesThreadLooper());

        mSubscriptionManager.addOnSubscriptionsChangedListener(mOnSubscriptionsChangedListener);

        mHandler = new Handler(headsetService.getStateMachinesThreadLooper());

        mOnSubscriptionsChangedListener = new HeadsetPhoneStateOnSubscriptionChangedListener();

        mSubscriptionManager.addOnSubscriptionsChangedListener(command -> mHandler.post(command),

                mOnSubscriptionsChangedListener);

    }

    /**

    private class HeadsetPhoneStateOnSubscriptionChangedListener

            extends OnSubscriptionsChangedListener {

        HeadsetPhoneStateOnSubscriptionChangedListener(Looper looper) {

            super(looper);

        HeadsetPhoneStateOnSubscriptionChangedListener() {

            super();

        }

        @Override