fix(android): 解决Android打包失败的问题

android/build.gradle

@@ -1,27 +1,39 @@
+def safeExtGet(prop, fallback) {
+    rootProject.ext.has(prop) ? rootProject.ext.get(prop) : fallback
+}
+
+buildscript {
+    if (project == rootProject) {
+        // The Android Gradle plugin is only required when opening the android folder stand-alone.
+        // This avoids unnecessary downloads and potential conflicts when the library is included as a
+        // module dependency in an application project.
+        repositories {
+            google()
+            jcenter()
+        }
+        dependencies {
+            classpath 'com.android.tools.build:gradle:3.5.2'
+        }
+    }
+}
+
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 27
-    buildToolsVersion "23.0.1"
-
+    compileSdkVersion safeExtGet('compileSdkVersion', 28)
+    buildToolsVersion safeExtGet('buildToolsVersion', '28.0.3')
     defaultConfig {
-        minSdkVersion 16
-        targetSdkVersion 27
+        minSdkVersion safeExtGet('minSdkVersion', 16)
+        targetSdkVersion safeExtGet('targetSdkVersion', 28)
         versionCode 1
         versionName "1.0"
-
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
-
     }
-    buildTypes {
-        release {
-            minifyEnabled false
-            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
-        }
+    lintOptions {
+        abortOnError false
     }
 }
 
 dependencies {
-    compile fileTree(include: ['*.jar'], dir: 'libs')
-    compile 'com.facebook.react:react-native:+'
+    implementation fileTree(include: ['*.jar'], dir: 'libs')
+    implementation 'com.facebook.react:react-native:+'
 }

android/src/main/java/com/beefe/picker/PickerViewModule.java

@@ -6,7 +6,6 @@
 import android.graphics.Color;
 import android.graphics.PixelFormat;
 import android.graphics.Typeface;
-import android.support.annotation.Nullable;
 import android.text.TextUtils;
 import android.view.Gravity;
 import android.view.View;
@@ -16,6 +15,8 @@
 import android.widget.TextView;
 import android.os.Build;
 
+import androidx.annotation.Nullable;
+
 import com.beefe.picker.util.MIUIUtils;
 import com.beefe.picker.view.OnSelectedListener;
 import com.beefe.picker.view.PickerViewAlone;