Added application shortcut extra to allow the Shell adding bubble.

Included an application shortcut extra in the arguments for system
drag and drop initiated from the taskbar. With this intent, the
Shell process can add an application shortcut bubble.

Bug: 388894910
Flag: com.android.wm.shell.enable_create_any_bubble
Test: Manual. Have a shortcut and app icons in the taskbar.
Drag and drop both items over the bubble drop zone.
Observe that items are added to the bubble bar.
video: http://recall/-/gx8ASgewUeUS3QYohfrd1J/fnHDKrNWzJEzRw6rgIm0fG

Change-Id: I232da417facb22919a2bebd23e712c1d877c218e