Add vertical layout support for Overview in portrait

WM is making changes which allows apps to maintain
their orientation independent of the orientation of
the foreground app. This allows recents to always start
in portrait even when the app currently running is in
landscape. This means we have to give the illusion of
a landscape oriented overview when user swipes up in
gesterual nav when launcher is started in portrait
configuration.

PagedOrientationHandler abstracts all coordinate specific
logic from Paged/RecentsView primarily, but also all
other dynamic calculations throughout launcher.
PagedViewOrientationState is the single point of exposure
to other classes that depend on those changes. The goal
is to also minimize holding state to allow for default
implementations of PagedOrientationHandler for all the
3p/Fallback classes. PagedViewOrientationState also
holds other data around rotation that isn't
specifically tied to view logic.

The fake landscape overview can be toggled with:
adb shell settings put global forced_rotation [0/1]

Fixes: 146176182
Change-Id: I65d8d4e9f92b93931cbe0053ccaf0cda8d2ffd6c