private void launchWhenSplashScreenReady(TrustedWebActivityIntentBuilder builder,
            @Nullable Runnable completionCallback) {
        Log.d(TAG, "Launching Trusted Web Activity.");
        Intent intent = builder.build(mSession);
        ContextCompat.startActivity(mContext, intent, null);
        // Remember who we connect to as the package that is allowed to delegate notifications
        // to us.
        TrustedWebActivityService.setVerifiedProvider(mContext, mProviderPackage);
        if (completionCallback != null) {
            completionCallback.run();
        }
    }
Similar to {@link #launch(Uri)}, but allows more customization.

@param twaBuilder {@link TrustedWebActivityIntentBuilder} containing the url to open, along with
optional parameters: status bar color, additional trusted origins, etc.
@param splashScreenStrategy {@link SplashScreenStrategy} to use for showing splash screens,
null if splash screen not needed.
@param completionCallback Callback triggered when the url has been opened.
customtabs/src/android/support/customtabs/trusted/TwaLauncher.java