[Android] Upgrade kotlinx

[Geoffrey Métais]

vlc-android | branch: master | Geoffrey Métais <geoffrey.metais at gmail.com> | Mon Jun 11 15:14:31 2018 +0200| [f4b7b7fad212440c0bf2de31cf0b37b92911a289] | committer: Geoffrey Métais

Upgrade kotlinx

> https://code.videolan.org/videolan/vlc-android/commit/f4b7b7fad212440c0bf2de31cf0b37b92911a289
---

 build.gradle | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/build.gradle b/build.gradle
index 0f7e3c482..2eb64b95e 100644
--- a/build.gradle
+++ b/build.gradle
@@ -2,7 +2,7 @@
 buildscript {
     ext.android_plugin_version = '3.1.3'
     ext.kotlin_version = '1.2.41'
-    ext.kotlinx_version = '0.22.2'
+    ext.kotlinx_version = '0.23.1'
     repositories {
         flatDir dirs: "gradle/plugins"
         google()