Trebuchet: Let's keep 2-button nav alive for a little longer

* Refactor to avoid breaking gesture nav

This partially reverts commit 9cddf4133befc721f2eb6a374b40fbb1b74f64ef.
This partially reverts commit 0130252c00ef268dfb80d9bff9c3da90bfffd7ff.

Change-Id: I1823de2a911f8a17c3716bc0b1b8e6c9c55d37cd
2 files changed