Seems like this method is new and isn't yet available in AndroidX stable version.
You can use this code to get this information on Android 7.1+:
B4X:
Dim p As Phone
If p.SdkVersion >= 25 Then
Dim ShortcutManager As JavaObject = ctxt.RunMethod("getSystemService", Array("shortcut"))
Dim pinned As List = ShortcutManager.RunMethod("getPinnedShortcuts", Null)
Log(pinned.Size)
End If