update for androidX

examples/basic/android/build.gradle

@@ -1,11 +1,20 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
+    ext {
+    buildToolsVersion = "28.0.3"
+    minSdkVersion = 19
+    compileSdkVersion = 28
+    targetSdkVersion = 28
+    supportLibVersion = "28.0.0"
+
+}
     repositories {
         jcenter()
+        google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.0'
+        classpath 'com.android.tools.build:gradle:3.4.1'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
@@ -15,6 +24,12 @@ buildscript {
 allprojects {
     repositories {
         mavenLocal()
+        maven {
+           url 'https://maven.google.com'
+        }
+        maven {
+           url "https://jitpack.io"
+        }
         jcenter()
         maven {
             // All of React Native (JS, Obj-C sources, Android binaries) is installed from npm