React-native 0.56 compatibility

Author: Andriy Slyusar

android/build.gradle

@@ -1,35 +1,27 @@
-
-buildscript {
-    repositories {
-        jcenter()
-    }
-
-    dependencies {
-        classpath 'com.android.tools.build:gradle:1.3.1'
-    }
+def safeExtGet(prop, fallback) {
+    rootProject.ext.has(prop) ? rootProject.ext.get(prop) : fallback
 }
 
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 23
-    buildToolsVersion "23.0.1"
+    compileSdkVersion safeExtGet('compileSdkVersion', 26)
+    buildToolsVersion safeExtGet('buildToolsVersion', '26.0.3')
 
     defaultConfig {
-        minSdkVersion 16
-        targetSdkVersion 22
+        minSdkVersion safeExtGet('minSdkVersion', 16)
+        targetSdkVersion safeExtGet('minSdkVersion', 26)
         versionCode 1
         versionName "1.0"
+        ndk {
+            abiFilters "armeabi-v7a", "x86"
+        }
     }
     lintOptions {
         abortOnError false
     }
 }
 
-repositories {
-    mavenCentral()
-}
-
 dependencies {
     compile 'com.facebook.react:react-native:+'
 }