Updates OptionsPopupView to allow non-resource strings/icons.

This will be needed for Smartspace which gets its menu options
from AiAi.

Test: Hard-coded strings passed to Smartspace from the fake
data Launcher plugin. Also verified could access the menu
using TalkBack.
Bug: 184179894

Change-Id: I724c09db18085585c7a5224e32c0d8973acdab7c