[Android] Upgrade Kotlin version

[Geoffrey Métais]

vlc-android | branch: master | Geoffrey Métais <geoffrey.metais at gmail.com> | Wed Jan 17 13:56:28 2018 +0100| [37c7199760f9feb7ae313e73985ca7d618f80580] | committer: Geoffrey Métais

Upgrade Kotlin version

> https://code.videolan.org/videolan/vlc-android/commit/37c7199760f9feb7ae313e73985ca7d618f80580
---

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

diff --git a/build.gradle b/build.gradle
index ff2f61713..88e0076b4 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,7 +1,7 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 buildscript {
     ext.android_plugin_version = '3.0.1'
-    ext.kotlin_version = '1.2.10'
+    ext.kotlin_version = '1.2.20'
     ext.kotlinx_version = '0.21.2'
     repositories {
         flatDir dirs: "gradle/plugins"