Update mobile specialpages to use executeWhenAvailable()

Even though these special pages are already in stable, they should
follow the same pattern as the others (the executeWhenAvailable()
pattern introduced in b287d31dc2e76c4b80f85c9a10add81749080d19).

Change-Id: I6f0ab5c45a50666886d9c6c5bdfc721a94e59fe1
Merge "Update mobile specialpages to use executeWhenAvailable()"