Update PieController.java

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