[google_maps_flutter] Out of developers preview, bump to 1.0.0 (#3091)

diff --git a/packages/google_maps_flutter/google_maps_flutter/CHANGELOG.md b/packages/google_maps_flutter/google_maps_flutter/CHANGELOG.md
index a37cb83..4192be5 100644
--- a/packages/google_maps_flutter/google_maps_flutter/CHANGELOG.md
+++ b/packages/google_maps_flutter/google_maps_flutter/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.0.0 - Out of developer preview  🎉.
+
+* Bump the minimal Flutter SDK to 1.22 where platform views are out of developer preview and performing better on iOS. Flutter 1.22 no longer requires adding the `io.flutter.embedded_views_preview` to `Info.plist` in iOS.
+
 ## 0.5.33
 
 * Keep handling deprecated Android v1 classes for backward compatibility.
diff --git a/packages/google_maps_flutter/google_maps_flutter/README.md b/packages/google_maps_flutter/google_maps_flutter/README.md
index 4f20672..bbf3e87 100644
--- a/packages/google_maps_flutter/google_maps_flutter/README.md
+++ b/packages/google_maps_flutter/google_maps_flutter/README.md
@@ -4,20 +4,6 @@
 
 A Flutter plugin that provides a [Google Maps](https://developers.google.com/maps/) widget.
 
-## Developers Preview Status
-The plugin relies on Flutter's new mechanism for embedding Android and iOS views.
-As that mechanism is currently in a developers preview, this plugin should also be
-considered a developers preview.
-
-Known issues are tagged with the [platform-views](https://github.com/flutter/flutter/labels/a%3A%20platform-views) and/or [maps](https://github.com/flutter/flutter/labels/p%3A%20maps) labels.
-
-To use this plugin on iOS you need to opt-in for the embedded views preview by
-adding a boolean property to the app's `Info.plist` file, with the key `io.flutter.embedded_views_preview`
-and the value `YES`.
-
-The API exposed by this plugin is not yet stable, and we expect some breaking changes to land soon.
-
-
 ## Usage
 
 To use this plugin, add `google_maps_flutter` as a [dependency in your pubspec.yaml file](https://flutter.io/platform-plugins/).
diff --git a/packages/google_maps_flutter/google_maps_flutter/pubspec.yaml b/packages/google_maps_flutter/google_maps_flutter/pubspec.yaml
index 9b87828..8d52203 100644
--- a/packages/google_maps_flutter/google_maps_flutter/pubspec.yaml
+++ b/packages/google_maps_flutter/google_maps_flutter/pubspec.yaml
@@ -1,7 +1,7 @@
 name: google_maps_flutter
 description: A Flutter plugin for integrating Google Maps in iOS and Android applications.
 homepage: https://github.com/flutter/plugins/tree/master/packages/google_maps_flutter/google_maps_flutter
-version: 0.5.33
+version: 1.0.0
 
 dependencies:
   flutter:
@@ -33,4 +33,4 @@
 
 environment:
   sdk: ">=2.1.0 <3.0.0"
-  flutter: ">=1.16.3 <2.0.0"
+  flutter: ">=1.22.0 <2.0.0"