I'm not sure that this is even possible to accomplish. The best I've managed to do so far is to set the background drawable as android.R.drawable.list_selector_background, which does at least show some touch feedback, but it looks horrendously ugly. It's not possible to use your own drawable in a RemoteView, and you can't use resources from your theme either (so R.attr.selectableItemBackgroundBorderless won't work).
Well, it appears that it's partially possible. android.R.attr.selectableItemBackground works fine, but android.R.attr.selectableItemBackgroundBorderless doesn't for some reason.
I'm not sure that this is even possible to accomplish. The best I've managed to do so far is to set the background drawable as
android.R.drawable.list_selector_background
, which does at least show some touch feedback, but it looks horrendously ugly. It's not possible to use your own drawable in a RemoteView, and you can't use resources from your theme either (so R.attr.selectableItemBackgroundBorderless won't work).