DatePickerDialogModule supports only FragmentActivity (#23371)

Summary:
Now RN has only ReactActivity which extends AppCompatActivity, subclass of FragmentActivity, therefore no need to check if activity is FragmentActivity or not. This PR changes DatePickerDialogModule to work only with FragmentActivity.

Also DialogFragment from Android is deprecated in API 28, and recommends to use DialogFragment from Support Library. Excerpt from DialogFragment documentation.

> **This class was deprecated in API level 28.**
> Use the Support Library DialogFragment for consistent behavior across all devices and access to Lifecycle.

**BREAKING CHANGE**: Brown field apps must extend FragmentActivity or its subclasses

[Android] [Changed] - DatePickerDialogModule supports only FragmentActivity
Pull Request resolved: #23371

Differential Revision: D14030765

Pulled By: cpojer

fbshipit-source-id: 3a1811102cf68b82c139f0e20b2fc8dab5d98b69

Author: dulmandakh

ReactAndroid/src/main/java/com/facebook/react/modules/datepicker/DatePickerDialogFragment.java

@@ -16,12 +16,12 @@
 import android.app.DatePickerDialog;
 import android.app.DatePickerDialog.OnDateSetListener;
 import android.app.Dialog;
-import android.app.DialogFragment;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.DialogInterface.OnDismissListener;
 import android.os.Build;
 import android.os.Bundle;
+import android.support.v4.app.DialogFragment;
 import android.widget.DatePicker;
 
 @SuppressLint("ValidFragment")

ReactAndroid/src/main/java/com/facebook/react/modules/datepicker/DatePickerDialogModule.java

@@ -7,18 +7,20 @@
 
 package com.facebook.react.modules.datepicker;
 
-import android.app.Activity;
+
 import android.app.DatePickerDialog.OnDateSetListener;
-import android.app.DialogFragment;
-import android.app.FragmentManager;
 import android.content.DialogInterface;
 import android.content.DialogInterface.OnDismissListener;
 import android.os.Bundle;
+import android.support.v4.app.DialogFragment;
+import android.support.v4.app.FragmentActivity;
+import android.support.v4.app.FragmentManager;
 import android.widget.DatePicker;
 import com.facebook.react.bridge.*;
 import com.facebook.react.common.annotations.VisibleForTesting;
 import com.facebook.react.module.annotations.ReactModule;
 
+import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 /**
@@ -46,7 +48,7 @@ public DatePickerDialogModule(ReactApplicationContext reactContext) {
   }
 
   @Override
-  public String getName() {
+  public @Nonnull String getName() {
     return DatePickerDialogModule.FRAGMENT_TAG;
   }
 
@@ -110,48 +112,28 @@ public void onDismiss(DialogInterface dialog) {
    */
   @ReactMethod
   public void open(@Nullable final ReadableMap options, Promise promise) {
-    Activity activity = getCurrentActivity();
+    FragmentActivity activity = (FragmentActivity) getCurrentActivity();
     if (activity == null) {
       promise.reject(
           ERROR_NO_ACTIVITY,
           "Tried to open a DatePicker dialog while not attached to an Activity");
       return;
     }
-    // We want to support both android.app.Activity and the pre-Honeycomb FragmentActivity
-    // (for apps that use it for legacy reasons). This unfortunately leads to some code duplication.
-    if (activity instanceof android.support.v4.app.FragmentActivity) {
-      android.support.v4.app.FragmentManager fragmentManager =
-          ((android.support.v4.app.FragmentActivity) activity).getSupportFragmentManager();
-      android.support.v4.app.DialogFragment oldFragment =
-          (android.support.v4.app.DialogFragment) fragmentManager.findFragmentByTag(FRAGMENT_TAG);
-      if (oldFragment != null) {
-        oldFragment.dismiss();
-      }
-      SupportDatePickerDialogFragment fragment = new SupportDatePickerDialogFragment();
-      if (options != null) {
-        final Bundle args = createFragmentArguments(options);
-        fragment.setArguments(args);
-      }
-      final DatePickerDialogListener listener = new DatePickerDialogListener(promise);
-      fragment.setOnDismissListener(listener);
-      fragment.setOnDateSetListener(listener);
-      fragment.show(fragmentManager, FRAGMENT_TAG);
-    } else {
-      FragmentManager fragmentManager = activity.getFragmentManager();
-      DialogFragment oldFragment = (DialogFragment) fragmentManager.findFragmentByTag(FRAGMENT_TAG);
-      if (oldFragment != null) {
-        oldFragment.dismiss();
-      }
-      DatePickerDialogFragment fragment = new DatePickerDialogFragment();
-      if (options != null) {
-        final Bundle args = createFragmentArguments(options);
-        fragment.setArguments(args);
-      }
-      final DatePickerDialogListener listener = new DatePickerDialogListener(promise);
-      fragment.setOnDismissListener(listener);
-      fragment.setOnDateSetListener(listener);
-      fragment.show(fragmentManager, FRAGMENT_TAG);
+
+    FragmentManager fragmentManager = activity.getSupportFragmentManager();
+    DialogFragment oldFragment = (DialogFragment) fragmentManager.findFragmentByTag(FRAGMENT_TAG);
+    if (oldFragment != null) {
+      oldFragment.dismiss();
+    }
+    DatePickerDialogFragment fragment = new DatePickerDialogFragment();
+    if (options != null) {
+      final Bundle args = createFragmentArguments(options);
+      fragment.setArguments(args);
     }
+    final DatePickerDialogListener listener = new DatePickerDialogListener(promise);
+    fragment.setOnDismissListener(listener);
+    fragment.setOnDateSetListener(listener);
+    fragment.show(fragmentManager, FRAGMENT_TAG);
   }
 
   private Bundle createFragmentArguments(ReadableMap options) {