Fixed bug #4228: move from jcenter() to mavenCentral()

SDL can use relinker. If it's enabled on your project, you need to update to version 1.4.3

android-project/build.gradle

@@ -2,7 +2,7 @@
 
 buildscript {
     repositories {
-        jcenter()
+        mavenCentral()
         google()
     }
     dependencies {
@@ -15,7 +15,7 @@ buildscript {
 
 allprojects {
     repositories {
-        jcenter()
+        mavenCentral()
         google()
     }
 }