Add license blocks

Author: aednlaxer

packages/google_maps_flutter/google_maps_flutter/example/lib/advanced_marker_icons.dart

@@ -1,3 +1,7 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 import 'package:flutter/material.dart';
 import 'package:google_maps_flutter_platform_interface/google_maps_flutter_platform_interface.dart';
 

packages/google_maps_flutter/google_maps_flutter/example/lib/advanced_markers_clustering.dart

@@ -1,3 +1,7 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 import 'package:flutter/material.dart';
 import 'package:google_maps_flutter_platform_interface/google_maps_flutter_platform_interface.dart';
 

packages/google_maps_flutter/google_maps_flutter_android/example/lib/advanced_marker_icons.dart

@@ -1,3 +1,7 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 import 'package:flutter/material.dart';
 import 'package:google_maps_flutter_platform_interface/google_maps_flutter_platform_interface.dart';
 

packages/google_maps_flutter/google_maps_flutter_android/example/lib/advanced_markers_clustering.dart

@@ -1,3 +1,7 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 import 'package:flutter/material.dart';
 import 'package:google_maps_flutter_platform_interface/google_maps_flutter_platform_interface.dart';
 

packages/google_maps_flutter/google_maps_flutter_ios/example/shared/maps_example_dart/lib/advanced_marker_icons.dart

@@ -1,3 +1,7 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 import 'package:flutter/material.dart';
 import 'package:google_maps_flutter_platform_interface/google_maps_flutter_platform_interface.dart';
 

packages/google_maps_flutter/google_maps_flutter_ios/example/shared/maps_example_dart/lib/advanced_markers_clustering.dart

@@ -1,3 +1,7 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 import 'package:flutter/material.dart';
 import 'package:google_maps_flutter_platform_interface/google_maps_flutter_platform_interface.dart';
 

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/advanced_marker.dart

@@ -1,3 +1,7 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 import 'dart:ui' show Offset;
 import 'package:flutter/foundation.dart';
 

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/glyph.dart

@@ -1,3 +1,7 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart' show Color;
 

packages/google_maps_flutter/google_maps_flutter_platform_interface/test/types/advanced_marker_test.dart

@@ -1,3 +1,6 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
 import 'package:flutter_test/flutter_test.dart';
 import 'package:google_maps_flutter_platform_interface/google_maps_flutter_platform_interface.dart';