Android :: Target Running Application With KeyEvent?

my goal is to target with a keyevent a specific application running either in foreground or background from a background service. I tried many solutions, but have not yet managed to do it. The few solutions tried (all from a background running service): With a broadcast, I tried to target the first application (for example the phone app) that would manage the key event

KeyEvent lKey1Up = new KeyEvent(KeyEvent.ACTION_UP,KeyEvent.KEYCODE_ENDCALL);
KeyEvent lKey1Dwn = new KeyEvent(KeyEvent.ACTION_DOWN,KeyEvent.KEYCODE_ENDCALL);
Intent lKey1UpIntent = new Intent(Intent.ACTION_MEDIA_BUTTON);
Intent lKey1DwnIntent = new Intent(Intent.ACTION_MEDIA_BUTTON);
lKey1UpIntent.putExtra(Intent.EXTRA_KEY_EVENT, lKey1Up);
lKey1DwnIntent.putExtra(Intent.EXTRA_KEY_EVENT, lKey1Dwn );
sendOrderedBroadcast(lKey1UpIntent, null);
sendOrderedBroadcast(lKey1DwnIntent, null);

=> Nothing happens with my foreground phone app when the broadcast is performed while I am in a phone call state (OFFHOOK). Indeed, I was nearly sure this would not work since I have no way to specificely target the phone app.............