O Emulador no meu android Studio não mostra a actionBar

import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class formTaxista extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_form_taxista);

        Button botaoSalvar = (Button) findViewById(R.id.formulario_salvar);
        botaoSalvar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(formTaxista.this, "Você clicou , Zebra!", Toast.LENGTH_SHORT).show();
                finish();
            }
        });
    }
    // mexendo na barra de menu
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.menu_form,menu);
        return super.onCreateOptionsMenu(menu);
    }
}

O manifest está assim

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.electro.taxi.taxi">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity
            android:name=".principalActivity"
            android:label="@string/app_name"
            android:theme="@style/AppTheme.NoActionBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".formTaxista"
            android:label="@string/title_activity_form_taxista"
            android:theme="@style/AppTheme.NoActionBar">

        </activity>
    </application>

</manifest>