Add isWideColorGamutEnabled to ReactActivityDelegate (facebook#43036)

Summary:
This adds support for enabling wide color gamut mode for ReactActivity per the wide gamut color [RFC](react-native-community/discussions-and-proposals#738).

## Changelog:

[ANDROID] [ADDED] - Add isWideColorGamutEnabled to ReactActivityDelegate

Pull Request resolved: facebook#43036

Test Plan:
Update RNTesterActivity.kt to enable wide color gamut:

```diff
  class RNTesterActivity : ReactActivity() {
    class RNTesterActivityDelegate(val activity: ReactActivity, mainComponentName: String) :
      // ...
      override fun getLaunchOptions() =
          if (this::initialProps.isInitialized) initialProps else Bundle()

+     override fun isWideColorGamutEnabled() = true
    }
```

Reviewed By: cortinico

Differential Revision: D55749124

Pulled By: cipolleschi

fbshipit-source-id: 44dd5631e1a2e429c86c01ed8747bbebbc8bdb3b

Author: ryanlntn

packages/react-native/ReactAndroid/api/ReactAndroid.api

@@ -128,6 +128,7 @@ public class com/facebook/react/ReactActivityDelegate {
 	public fun getReactInstanceManager ()Lcom/facebook/react/ReactInstanceManager;
 	protected fun getReactNativeHost ()Lcom/facebook/react/ReactNativeHost;
 	protected fun isFabricEnabled ()Z
+	protected fun isWideColorGamutEnabled ()Z
 	protected fun loadApp (Ljava/lang/String;)V
 	public fun onActivityResult (IILandroid/content/Intent;)V
 	public fun onBackPressed ()Z

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/ReactActivityDelegate.java

@@ -10,7 +10,9 @@
 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
+import android.content.pm.ActivityInfo;
 import android.content.res.Configuration;
+import android.os.Build;
 import android.os.Bundle;
 import android.view.KeyEvent;
 import androidx.annotation.Nullable;
@@ -102,6 +104,9 @@ public String getMainComponentName() {
   public void onCreate(Bundle savedInstanceState) {
     String mainComponentName = getMainComponentName();
     final Bundle launchOptions = composeLaunchOptions();
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O && isWideColorGamutEnabled()) {
+      mActivity.getWindow().setColorMode(ActivityInfo.COLOR_MODE_WIDE_COLOR_GAMUT);
+    }
     if (ReactFeatureFlags.enableBridgelessArchitecture) {
       mReactDelegate =
           new ReactDelegate(getPlainActivity(), getReactHost(), mainComponentName, launchOptions);
@@ -217,4 +222,13 @@ protected Activity getPlainActivity() {
   protected boolean isFabricEnabled() {
     return ReactFeatureFlags.enableFabricRenderer;
   }
+
+  /**
+   * Override this method if you wish to selectively toggle wide color gamut for a specific surface.
+   *
+   * @return true if wide gamut is enabled for this Activity, false otherwise.
+   */
+  protected boolean isWideColorGamutEnabled() {
+    return false;
+  }
 }