Frameworks: take  mPieScale into account to calculate estimated PIE width

if scaled size of the PIE is over or under the default size
the pie was either no using the whole screen space or
it was cutted off. To solve this take scale value
into account when calculating estimated width

greetings SlimRoms

Change-Id: Iccfc8362c0019e3b6ff4bd8066c313c67116c014
Framworks: disable observer and receiver if PIE is disabled

on high end devices that is maybe not needed. But there
is in general no need to enable the obeserver/receiver
when PIE is disabled (or expanded mode is off)
This change destroy and disables the PIE in most parts
when it is disabled. + a small doubel register
correction

greetings SlimRoms

PatchSet 2:
- remove PieLayout observer completly - thanks Jens

PatchSet 3:
- remove unnecessary call to setupSnapPoints()
- reuse already created snap points

PatchSet 4:
- small corrections on setupSnapPoints() and call
- remove not needed second call of PieController attachTo()
- disable TelephonyManager listener

PatchSet 5:
- fix up detach logic

PatchSet 7:
- cleanup

PatchSet 8:
- Effective Java rule #41
- fixed some pie controller leak

Change-Id: I8ef8797e7d4f8ee73d31a8296f5747415567bbda