PIE: Improve assistant handling

Run it from SearchPanelView and determinate before, at PieMenu creation,
if we have any assistant available or not.

Some cleanup too.

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Quicksettings: Add separate dimension for dual switch icon

Support Themers (for ex the ones who change QS icon sizes).
Right now it streams default one that is themed, and a bigger icon
theme will mess it up.

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
PEEK: Sensors improvements

- Bring some fixes to the algorithm thanks to @D4rKn3sSyS
- Cleanup

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Themes: Fix wallpaper chooser crash

Fix AOSPA-477
VolumePanel: Fix Theme Engine support with On-The-Spot dialog

Our on the spot feature needs to write to system. Since VolumePanel when is
recreated uses theme engine context, pass to on the spot dialog always the
first system initialized one. Thanks to @David96 helping find this out :)

Fix AOSPA-482

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Change-Id: I492cd8e24b09d856d23697b84113664379703cf1