Este error ha sido persistente por siempre. (Me aseguré de que "Google Maps Android API v2" esté activado).

Aquí está el MainActivity.java:

package com.example.maptest;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.Menu;

public class MainActivity extends FragmentActivity { 

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

    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }     
}

Manifiesto:

    <uses-sdk
        android:minSdkVersion="17"
        android:targetSdkVersion="17" />

     <permission
        android:name="com.example.maptest.permission.MAPS_RECEIVE"
        android:protectionLevel="signature" />
    <uses-permission 
        android:name="com.google.android.providers.gsf.permission.READ_GSERVICES"/>


    <uses-permission android:name="com.example.maptest.permission.MAPS_RECEIVE" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />


    <uses-feature
        android:name="android.hardware.location"
        android:required="true" />
    <uses-feature
        android:name="android.hardware.location.network"
        android:required="true" />
    <uses-feature android:name="android.hardware.location.gps" />
    <uses-feature
        android:name="android.hardware.wifi"
        android:required="true" />

    <uses-feature
        android:glEsVersion="0x00020000"
        android:required="true" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >

        <uses-library android:name="com.google.android.maps" />

        <activity
            android:name="com.example.maptest.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <meta-data
            android:name="com.google.android.maps.v2.API_KEY"
            android:value="AIzaSyAoDwhSzOopQ3g8NBe7d0WblR72TkmnVPU" />


    </application>

</manifest>

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:map="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >


    <fragment 
    class="com.google.android.gms.maps.SupportMapFragment"
    android:id="@+id/map"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:name="com.google.android.gms.maps.MapFragment"/>

</RelativeLayout>

¡Por favor ayuda! No estoy seguro de qué salió mal ... aunque terminé siguiendo / combinando varios tutoriales porque ninguno de ellos trabajó por su cuenta.