Revert "navbar: remove stock 3-button layout float on phones to properly size custom keys"

This changes the shape of the stock 3 button layout for no good reason.

Plus, Dan said to. trololol.

This reverts commit 5e38e0482617f07acc8c82285d2b9e2aea7fb1e2.

Change-Id: I5c92e8a55a0d48bd193ad186f3cf3ec9c996acc1
Merge "Revert "navbar: remove stock 3-button layout float on phones to properly size custom keys"" into kk44