Fix: Fix excessive binder calls in SystemUI.

The updateAvailableAppsAndShortcutsAsync() method in LaunchApp.kt
made excessive API calls, causing high system load.

A loop repeatedly invoked getIntentForIntentSender() and other APIs,
leading to increased binder calls.

To optimize, server-side aggregation was implemented in LauncherAppsService,
consolidating multiple requests into a single operation.

This significantly reduces performance overhead and system load.

Flag: android.app.optimize_get_apps_and_shortcuts
Test: atest LauncherAppsTest
Bug: 364133831
Change-Id: Id7f7e309f5dafb518f63370aed473276a920e886