chore(cronet_http): prepare 1.9.0 (#1924)

pkgs/cronet_http/CHANGELOG.md

diff --git a/pkgs/cronet_http/CHANGELOG.md b/pkgs/cronet_http/CHANGELOG.md
index 4d885f4..2417106 100644
--- a/pkgs/cronet_http/CHANGELOG.md
+++ b/pkgs/cronet_http/CHANGELOG.md
@@ -1,4 +1,4 @@
-## 1.9.0-wip
+## 1.9.0
 
 * Add `CronetEngine.startNetLogToFile` and `CronetEngine.stopNetLog`.
 * Decode Java `CronetException` into Dart equivalents.

pkgs/cronet_http/pubspec.yaml

diff --git a/pkgs/cronet_http/pubspec.yaml b/pkgs/cronet_http/pubspec.yaml
index c82247a..45e97af 100644
--- a/pkgs/cronet_http/pubspec.yaml
+++ b/pkgs/cronet_http/pubspec.yaml
@@ -1,5 +1,5 @@
 name: cronet_http
-version: 1.9.0-wip
+version: 1.9.0
 description: >-
   An Android Flutter plugin that provides access to the Cronet HTTP client.
 repository: https://github.com/dart-lang/http/tree/master/pkgs/cronet_http