Update build.gradle

android/build.gradle

@@ -1,31 +1,38 @@
+buildscript {
+    repositories {
+        google()
+        jcenter()
+    }
+
+    dependencies {
+        classpath("com.android.tools.build:gradle:3.4.1")
+    }
+}
+
 apply plugin: 'com.android.library'
 
-def DEFAULT_COMPILE_SDK_VERSION = 23
-def DEFAULT_BUILD_TOOLS_VERSION = "23.0.2"
-def DEFAULT_TARGET_SDK_VERSION = 23
-def DEFAULT_SUPPORT_LIB_VERSION = "23.1.0"
+def safeExtGet(prop, fallback) {
+    rootProject.ext.has(prop) ? rootProject.ext.get(prop) : fallback
+}
 
 android {
-    compileSdkVersion rootProject.hasProperty('compileSdkVersion') ? rootProject.compileSdkVersion : DEFAULT_COMPILE_SDK_VERSION
-    buildToolsVersion rootProject.hasProperty('buildToolsVersion') ? rootProject.buildToolsVersion : DEFAULT_BUILD_TOOLS_VERSION
+    compileSdkVersion safeExtGet('compileSdkVersion', 28)
+    buildToolsVersion safeExtGet('buildToolsVersion', '28.0.3')
 
     defaultConfig {
-        minSdkVersion 16
-        targetSdkVersion rootProject.hasProperty('targetSdkVersion') ? rootProject.targetSdkVersion : DEFAULT_TARGET_SDK_VERSION
+        minSdkVersion safeExtGet('minSdkVersion', 16)
+        targetSdkVersion safeExtGet('targetSdkVersion', 28)
         versionCode 1
         versionName "1.0"
     }
-    buildTypes {
-        release {
-            minifyEnabled false
-        }
+    lintOptions {
+        abortOnError false
     }
 }
 
-def supportVersion = rootProject.hasProperty('supportLibVersion') ? rootProject.supportLibVersion : DEFAULT_SUPPORT_LIB_VERSION
+def supportVersion = safeExtGet('supportLibVersion', '28.0.0')
 
 dependencies {
-    compile fileTree(include: ['*.jar'], dir: 'libs')
-    compile 'com.android.support:appcompat-v7:${supportVersion}'
-    compile 'com.facebook.react:react-native:+'
+    implementation "com.android.support:appcompat-v7:${supportVersion}"
+    implementation 'com.facebook.react:react-native:+'
 }