Revert "[google_sign_in] Migrate to new pubspec plugins schema (flutt…

…er#2371)"

This reverts commit 1e82c75.

# Conflicts:
#	packages/google_sign_in/google_sign_in/CHANGELOG.md
#	packages/google_sign_in/google_sign_in/pubspec.yaml

packages/google_sign_in/google_sign_in/CHANGELOG.md

@@ -1,3 +1,13 @@
+## 4.0.17
+
+* Add missing documentation and fix an unawaited future in the example app.
+
+## 4.0.16
+
+* Remove the deprecated `author:` field from pubspec.yaml
+* Migrate the plugin to the pubspec platforms manifest.
+* Require Flutter SDK 1.10.0 or greater.
+
 ## 4.0.15
 
 * Export SignInOption from interface since it is used in the frontend as a type.
@@ -51,8 +61,8 @@
 
 ## 4.0.3
 
-* Update guava to `27.0.1-android`.	
-* Add correct @NonNull annotations to reduce compiler warnings.	
+* Update guava to `27.0.1-android`.
+* Add correct @NonNull annotations to reduce compiler warnings.
 
 ## 4.0.2
 

packages/google_sign_in/google_sign_in/pubspec.yaml

@@ -1,15 +1,17 @@
 name: google_sign_in
 description: Flutter plugin for Google Sign-In, a secure authentication system
   for signing in with a Google account on Android and iOS.
-author: Flutter Team <flutter-dev@googlegroups.com>
 homepage: https://github.com/flutter/plugins/tree/master/packages/google_sign_in/google_sign_in
-version: 4.0.15
+version: 4.0.17
 
 flutter:
   plugin:
-    androidPackage: io.flutter.plugins.googlesignin
-    iosPrefix: FLT
-    pluginClass: GoogleSignInPlugin
+    platforms:
+      android:
+        package: io.flutter.plugins.googlesignin
+        pluginClass: GoogleSignInPlugin
+      ios:
+        pluginClass: FLTGoogleSignInPlugin
 
 dependencies:
   google_sign_in_platform_interface: ^1.0.0
@@ -24,4 +26,4 @@ dev_dependencies:
 
 environment:
   sdk: ">=2.0.0-dev.28.0 <3.0.0"
-  flutter: ">=1.5.0 <2.0.0"
+  flutter: ">=1.10.0 <2.0.0"