Adapt navigation bar's long press behaviour for pie controls (DRAFT)

This commit brings the navigation bar long press behaviour to
pie controls.

Two things will be considered for long press:
* Long press on HOME will open Google Now.
* Long press on BACK will kill an application if enabled within
  the debug options.

Patch Set #2:
* Jacob's colours

Change-Id: I8cfa87a5be0678f0452011d85d427439d7cf31e9