SystemUI: Export RecordingService for External Usage

Signed-off-by: cjybyjk <cjybyjk@zjnu.edu.cn>
[nullxception: simplify start handling and adapt it to 12L]
Signed-off-by: Nauval Rizky <enuma.alrizky@gmail.com>
Signed-off-by: Rahmad Adi Pratama <OhMyVenyx@proton.me>

Author: cjybyjk

packages/SystemUI/src/com/android/systemui/screenrecord/RecordingService.java

@@ -221,6 +221,11 @@ public int onStartCommand(Intent intent, int flags, int startId) {
                 // Close quick shade
                 sendBroadcast(new Intent(Intent.ACTION_CLOSE_SYSTEM_DIALOGS));
                 break;
+            case ACTION_SHOW_DIALOG:
+                if (mController != null) {
+                    mController.createScreenRecordDialog(this, null).show();
+                }
+                break;
             case ACTION_DELETE:
                 // Close quick shade
                 sendBroadcast(new Intent(Intent.ACTION_CLOSE_SYSTEM_DIALOGS));