title: google maps showing blank screen
body: <p>I'm trying to display a google maps in a very simple application (a new project with just a google maps Activity) the manifest has the permissions: </p>
  
  <pre><code>&lt;manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.example.ivan.pruebamaps"&gt;
  
  &lt;uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /&gt;
  &lt;uses-permission android:name="android.permission.INTERNET" /&gt;
  &lt;application
  android:allowBackup="true"
  android:icon="@mipmap/ic_launcher"
  android:label="@string/app_name"
  android:roundIcon="@mipmap/ic_launcher_round"
  android:supportsRtl="true"
  android:theme="@style/AppTheme"&gt;
  
  
  &lt;meta-data
      android:name="com.google.android.geo.API_KEY"
      android:value="@string/google_maps_key" /&gt;
  
  &lt;activity
      android:name=".MapsActivity"
      android:label="@string/title_activity_maps"&gt;
      &lt;intent-filter&gt;
          &lt;action android:name="android.intent.action.MAIN" /&gt;
  
          &lt;category android:name="android.intent.category.LAUNCHER" /&gt;
      &lt;/intent-filter&gt;
  &lt;/activity&gt;
  &lt;/application&gt;
  
      &lt;/manifest&gt;
  </code></pre>
  
  <p>I have a valid key in @string/google_maps_key.</p>
  
  <p>The mainActivity it's untouched, the same as it's created in android studio.</p>
  
  <pre><code>public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
  private GoogleMap mMap;
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_maps);
      // Obtain the SupportMapFragment and get notified when the map is ready to be used.
      SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
              .findFragmentById(R.id.map);
      mapFragment.getMapAsync(this);
  }
  
  
  @Override
  public void onMapReady(GoogleMap googleMap) {
      mMap = googleMap;
  
      // Add a marker in Sydney and move the camera
      LatLng sydney = new LatLng(-34, 151);
      mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
      mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
  }
  }
  </code></pre>
  
  <p>The same happens with the layout file activity_maps:</p>
  
  <pre><code>&lt;fragment xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:map="http://schemas.android.com/apk/res-auto"
      xmlns:tools="http://schemas.android.com/tools"
      android:id="@+id/map"
      android:name="com.google.android.gms.maps.SupportMapFragment"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      tools:context="com.example.ivan.pruebamaps.MapsActivity" /&gt;
  </code></pre>
  
  <p>This is my gradle file if that helps :</p>
  
  <pre><code>apply plugin: 'com.android.application'
  
  android {
      compileSdkVersion 25
      buildToolsVersion "25.0.2"
      defaultConfig {
          applicationId "com.example.ivan.pruebamaps"
          minSdkVersion 15
          targetSdkVersion 25
          versionCode 1
          versionName "1.0"
          testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  }
  
  dependencies {
      compile fileTree(dir: 'libs', include: ['*.jar'])
      androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
          exclude group: 'com.android.support', module: 'support-annotations'
      })
      compile 'com.android.support:appcompat-v7:25.2.0'
      compile 'com.google.android.gms:play-services-maps:10.2.0'
      testCompile 'junit:junit:4.12'
  }
  </code></pre>
  
  <p>When i execute the app i just get a screen with a blank screen and the Google logo in the left bottom corner. I'm trying in a emulated nexus 5, and in a samsung galaxy s6, neither works.</p>