Error while extending the main activity

I am using NS 6.5 Core and I am following the example from https://v6.docs.nativescript.org/core-concepts/android-runtime/advanced-topics/extend-application-activity#extending-activity.

I have cleaned up my project, deleting the platforms, hooks, and node_modules folders. When I build the app, I get the following error: Class "org.myApp.MainActivity" not found.

Here is my code:

activity.android.ts:

import { setActivityCallbacks, AndroidActivityCallbacks } from "tns-core-modules/ui/frame";

@JavaProxy("org.myApp.MainActivity")
class Activity extends androidx.appcompat.app.AppCompatActivity {
    public isNativeScriptActivity;

    private _callbacks: AndroidActivityCallbacks;

    public onCreate(savedInstanceState: android.os.Bundle): void {
        // Set the isNativeScriptActivity in onCreate (as done in the original NativeScript activity code)
        // The JS constructor might not be called because the activity is created from Android.
        this.isNativeScriptActivity = true;
        if (!this._callbacks) {
            setActivityCallbacks(this);
        }

        this._callbacks.onCreate(this, savedInstanceState, this.getIntent(), super.onCreate);
    }

    public onSaveInstanceState(outState: android.os.Bundle): void {
        this._callbacks.onSaveInstanceState(this, outState, super.onSaveInstanceState);
    }

    public onStart(): void {
        this._callbacks.onStart(this, super.onStart);
    }

    public onStop(): void {
        this._callbacks.onStop(this, super.onStop);
    }

    public onDestroy(): void {
        this._callbacks.onDestroy(this, super.onDestroy);
    }

    public onBackPressed(): void {
        this._callbacks.onBackPressed(this, super.onBackPressed);
    }

    public onRequestPermissionsResult(requestCode: number, permissions: Array<string>, grantResults: Array<number>): void {
        this._callbacks.onRequestPermissionsResult(this, requestCode, permissions, grantResults, undefined /*TODO: Enable if needed*/);
    }

    public onActivityResult(requestCode: number, resultCode: number, data: android.content.Intent): void {
        this._callbacks.onActivityResult(this, requestCode, resultCode, data, super.onActivityResult);
    }
}

webpack.config.js:

const appComponents = env.appComponents || [];
    appComponents.push(...[
        "tns-core-modules/ui/frame",
        "tns-core-modules/ui/frame/activity",
        resolve(__dirname, "app/activity.android.ts"),
    ]);

AndroidManifest.xml:

<activity android:name="org.myApp.MainActivity" android:label="@string/title_activity_kimera" android:configChanges="keyboard|keyboardHidden|orientation|screenSize|smallestScreenSize|screenLayout|locale|uiMode" android:theme="@style/LaunchScreenTheme">
...
</activity>
<activity android:name="com.tns.ErrorReportActivity" />

Any suggestions on how to proceed?

Start with app/activity.android.ts, webpack.config.js, and AndroidManifest.xml, then reproduce the build after the reported cleanup. Trace whether the declared org.myApp.MainActivity is included in the generated Android output; done means the build completes and the activity can be found at launch.