public class ActivityBuy extends AppCompatActivity {
IabHelper mHelper;
public static final int BUY_CODE = 13;
IInAppBillingService mService;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);  // <== строка 31
    setContentView(R.layout.dialog_buy);

    findViewById(R.id.dialogExit).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            finish();
        }
    });
    findViewById(R.id.dialogBuy).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            try {
                buyFullResolve();
            } catch (RemoteException e) {
                e.printStackTrace();
            }
            finish();
        }
    });

    Intent serviceIntent = new Intent("com.android.vending.billing.InAppBillingService.BIND");
    serviceIntent.setPackage("com.android.vending");
    bindService(serviceIntent, mServiceConn, Context.BIND_AUTO_CREATE);

    String base64EncodedPublicKey = getString(R.string.licence);

    mHelper = new IabHelper(this, base64EncodedPublicKey);

    mHelper.startSetup(new IabHelper.OnIabSetupFinishedListener() {
        public void onIabSetupFinished(IabResult result) {
            if (!result.isSuccess()) {
                Log.d("ttt", "Problem setting up In-app Billing: " + result);
            } else {
                Log.d("ttt", "Success: " + result);
                mHelper.queryInventoryAsync(mGotInventoryListener);
            }
        }
    });
}

IabHelper.QueryInventoryFinishedListener mGotInventoryListener
        = new IabHelper.QueryInventoryFinishedListener() {
    public void onQueryInventoryFinished(IabResult result, Inventory inventory) {
        if (result.isFailure()) {
            StaticToaster.makeToaster(getLayoutInflater(), ActivityBuy.this, getString(R.string.noconnection), true, true);
        } else {
            //
        }
    }
};


public void buyFullResolve() throws RemoteException {
    ArrayList<String> skuList = new ArrayList<String>();
    skuList.add(getString(R.string.buyFullID));
    Bundle querySkus = new Bundle();
    querySkus.putStringArrayList("ITEM_ID_LIST", skuList);

    try {
        if (mHelper != null) mHelper.flagEndAsync();
        mHelper.launchPurchaseFlow(this, getString(R.string.buyFullID), BUY_CODE, mPurchaseFinishedListener, getString(R.string.randomKey));
    } catch (IllegalStateException e) {
        StaticToaster.makeToaster(getLayoutInflater(), this, "Покупка не удалась. Попробуйте через несколько секунд.", false, false);
    }
}

IabHelper.OnIabPurchaseFinishedListener mPurchaseFinishedListener
        = new IabHelper.OnIabPurchaseFinishedListener() {
    public void onIabPurchaseFinished(IabResult result, Purchase purchase) {
        if (result.isFailure()) {
            Log.d("ttt", "Error purchasing: " + result);
            setResult(RESULT_CANCELED);
        } else if (purchase.getSku().equals(getString(R.string.buyFullID))) {
            MyLab.get(ActivityBuy.this).setFullVersion(true);
            StaticToaster.makeToaster(getLayoutInflater(), ActivityBuy.this, getString(R.string.fullSuccess), false, false);

            setResult(RESULT_OK);
            finish();
        }
    }
};

ServiceConnection mServiceConn = new ServiceConnection() {
    @Override
    public void onServiceDisconnected(ComponentName name) {
        mService = null;
    }

    @Override
    public void onServiceConnected(ComponentName name,
                                   IBinder service) {
        mService = IInAppBillingService.Stub.asInterface(service);
    }
};

private void queryPurchasedItems() {
    if (mHelper.isSetupDone() && !mHelper.isAsyncInProgress()) {
        mHelper.queryInventoryAsync(mGotInventoryListener);
    }
}

<style name="myDialogStyle" parent="Theme.AppCompat.Dialog.Alert">
    <item name="windowActionBar">false</item>
    <item name="windowNoTitle">true</item>
</style>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">

<TextView
    style="@style/textStyle"
    android:text="@string/buyFullHeader"
    android:id="@+id/header"/>

<TextView
    android:id="@+id/dialogHeaderText"
    style="@style/textStyle"
    android:text="@string/buyFullVersion" />

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal">

    <Button
        android:id="@+id/dialogExit"
        android:text="@string/back"
     style="@style/dialogButton"/>

    <Button
        android:id="@+id/dialogBuy"
        android:text="@string/buy"
        style="@style/dialogButton"/>

</LinearLayout>

compileSdkVersion 27
buildToolsVersion "27.0.3"

defaultConfig {
    applicationId "id"
    minSdkVersion 14
    targetSdkVersion 27
    versionCode 1
    versionName "1.1"
}