Flag missing DefaultHardwareBackBtnHandler interface in bridgeless too (#43487)

Summary:
Pull Request resolved: #43487

Inconsistent between bridge and bridgeless, but if you forget to implement this interface, ReactDelegate will silently not do anything in bridgeless.

Changelog: [Android] Enforce Activities using ReactDelegate implement DefaultHardwareBackBtnHandler.

Reviewed By: arushikesarwani94

Differential Revision: D54900747

fbshipit-source-id: 5dd31d4f81e4ec37e1c3ee906be836a8a9c6a944

Author: javache

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

@@ -82,20 +82,17 @@ public ReactDelegate(
   }
 
   public void onHostResume() {
+    if (!(mActivity instanceof DefaultHardwareBackBtnHandler)) {
+      throw new ClassCastException(
+          "Host Activity does not implement DefaultHardwareBackBtnHandler");
+    }
     if (ReactFeatureFlags.enableBridgelessArchitecture) {
-      if (mActivity instanceof DefaultHardwareBackBtnHandler) {
-        mReactHost.onHostResume(mActivity, (DefaultHardwareBackBtnHandler) mActivity);
-      }
+      mReactHost.onHostResume(mActivity, (DefaultHardwareBackBtnHandler) mActivity);
     } else {
       if (getReactNativeHost().hasInstance()) {
-        if (mActivity instanceof DefaultHardwareBackBtnHandler) {
-          getReactNativeHost()
-              .getReactInstanceManager()
-              .onHostResume(mActivity, (DefaultHardwareBackBtnHandler) mActivity);
-        } else {
-          throw new ClassCastException(
-              "Host Activity does not implement DefaultHardwareBackBtnHandler");
-        }
+        getReactNativeHost()
+            .getReactInstanceManager()
+            .onHostResume(mActivity, (DefaultHardwareBackBtnHandler) mActivity);
       }
     }
   }