Fixed compiling issue in release config.

Author: phongcao

android/build.gradle

@@ -1,11 +1,11 @@
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 26
+    compileSdkVersion 28
 
     defaultConfig {
         minSdkVersion 16
-        targetSdkVersion 26
+        targetSdkVersion 28
         versionCode 1
         versionName "1.0"
         ndk {
@@ -24,7 +24,7 @@ dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation 'com.facebook.react:react-native:+'
     implementation 'com.google.firebase:firebase-messaging:17.6.0'
-    implementation 'com.android.support:appcompat-v7:26.1.0'
+    implementation 'com.android.support:appcompat-v7:28.0.0'
     implementation 'com.microsoft.azure:notification-hubs-android-sdk:0.4@aar'
     implementation 'com.microsoft.azure:azure-notifications-handler:1.0.1@aar'
 }