chore(cronet_http): Prepare to release 1.6.0 (#1833)

diff --git a/pkgs/cronet_http/CHANGELOG.md b/pkgs/cronet_http/CHANGELOG.md
index 1128d56..d557705 100644
--- a/pkgs/cronet_http/CHANGELOG.md
+++ b/pkgs/cronet_http/CHANGELOG.md

@@ -1,4 +1,4 @@
-## 1.6.0-wip
+## 1.6.0
 
 * Upgrade the `cronet-embedded` dependency to `141.7340` version to
   support 16 KB page sizes. `cronet-embedded` has target SDK version of 24.

diff --git a/pkgs/cronet_http/pubspec.yaml b/pkgs/cronet_http/pubspec.yaml
index 0bfa1d7..258f01e 100644
--- a/pkgs/cronet_http/pubspec.yaml
+++ b/pkgs/cronet_http/pubspec.yaml

@@ -1,5 +1,5 @@
 name: cronet_http
-version: 1.6.0-wip
+version: 1.6.0
 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