Revert onCreate changes

Revert ReaderSdk.initialize changes in TatsuUkraine:flutter-3. This change causes the application to crash whenever the app is background and the app has been initialized before.

Author: WhatsEmo

android/src/main/java/com/squareup/sdk/reader/flutter/SquareReaderSdkFlutterPlugin.java

@@ -15,7 +15,6 @@
 */
 package com.squareup.sdk.reader.flutter;
 
-import android.app.Activity;
 import android.content.Context;
 
 import androidx.annotation.NonNull;
@@ -40,8 +39,6 @@ public class SquareReaderSdkFlutterPlugin implements MethodCallHandler, FlutterP
   private CheckoutModule checkoutModule;
   private ReaderSettingsModule readerSettingsModule;
   private StoreCustomerCardModule storeCustomerCardModule;
-  private Activity currentActivity;
-  private static boolean sdkInitialized = false;
 
   public static void registerWith(Registrar registrar) {
     SquareReaderSdkFlutterPlugin instance = new SquareReaderSdkFlutterPlugin(registrar.activity());
@@ -68,16 +65,13 @@ private void init(Context context) {
   }
 
   private void setContextForModules(final Activity activity) {
-    currentActivity = activity;
     checkoutModule.setContext(activity);
     readerSettingsModule.setContext(activity);
     storeCustomerCardModule.setContext(activity);
   }
 
   @Override
   public void onMethodCall(MethodCall call, @NonNull Result result) {
-    initializeReaderSdk();
-
     String methodName = call.method;
     switch (methodName) {
       case "isAuthorized":
@@ -151,13 +145,4 @@ public void onReattachedToActivityForConfigChanges(@NonNull ActivityPluginBindin
   public void onDetachedFromActivity() {
 
   }
-
-  private void initializeReaderSdk() {
-    if (sdkInitialized) {
-      return;
-    }
-
-    ReaderSdk.initialize(currentActivity.getApplication());
-    sdkInitialized = true;
-  }
 }

example/android/app/src/main/java/com/example/flutter/squareup/sdk/reader/MainActivity.kt

@@ -15,8 +15,17 @@ limitations under the License.
 */
 package com.example.flutter.squareup.sdk.reader;
 
-import io.flutter.embedding.android.FlutterActivity
+import androidx.annotation.NonNull;
 
-class MainActivity: FlutterActivity() {
+import io.flutter.embedding.android.FlutterActivity;
+import io.flutter.embedding.engine.FlutterEngine;
+import io.flutter.plugins.GeneratedPluginRegistrant;
+
+public class MainActivity extends FlutterActivity {
+
+    @Override
+    public void configureFlutterEngine(@NonNull FlutterEngine flutterEngine) {
+        GeneratedPluginRegistrant.registerWith(flutterEngine);
+    }
 }
 

example/android/app/src/main/java/com/example/flutter/squareup/sdk/reader/MainApplication.kt

@@ -15,7 +15,22 @@ limitations under the License.
 */
 package com.example.flutter.squareup.sdk.reader;
 
-import io.flutter.app.FlutterApplication
+import android.app.Activity;
 
-class MainApplication: FlutterApplication() {
+import androidx.annotation.CallSuper;
+
+import com.squareup.sdk.reader.ReaderSdk;
+import io.flutter.app.FlutterApplication;
+
+import io.flutter.view.FlutterMain;
+
+
+public class MainApplication extends FlutterApplication {
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        ReaderSdk.initialize(this);
+        FlutterMain.startInitialization(this);
+    }
 }