Bug 1046564 - Should display normal priority message of STK_CMD_DISPLAY_TEXT command while device is Settings

patch for v1.3t to support display normal priority text message on settings app
It's not supported in 1.3 - https://bugzilla.mozilla.org/show_bug.cgi?id=1015833#c57

AFAIK, WindowManager.getDisplayedApp() only answers the origin so no "isHomescreen" attribute exists