Pie controls: Introducing a pie delivery service

To make pie controls more reliable, it is neccessary to detect
trigger actions directly from the input stream.
This commit introduces a new system service, that filters all
input events in front of the input dispatcher to detect pie activations.

This commit introduces:
* A new system server local API in the input manager service to register
  secondary input filters. These filters are behind the default
  accessibility filter but before the input event dispatching of
  the android framework.
* A new system service, that binds to the new API to listen for pie
  activation gestures.
* A non-public manager class providing access to the newly created pie
  service.

The service manager name of the service is "pieservice". The non-public
AIDL interface of the service is IPieService.aidl. To register a new
pie activation listener the INJECT_INPUT permission is needed. The
service state can be dumped by the "dumpsys pieservice" command.

Note: This commit only introduces the pie service. There is another
commit, that binds the actual pie controls to the pie service.

Patch Set #1:
* The pie service is currently disabled by default and needs to be
  enabled by device overlays (see config.xml / config_allowPieService).

Patch Set #2:
* Activation fixes
* Debug dump improvements

Patch Set #4:
* Added systrace support (TRACE_INPUT_TAG)
* Switch default to enable service on all devices.
* Moved Position to com.internal.android.utils.pie.*
* Some more code rearrangements

Patch Set #5:
* Rebase

Patch Set #6:
* Cover more corner cases on PieInputFilter
* Adjust gesture time out

Patch Set #7:
* Do not send events that are from the past
* Recycle all events

Patch Set #8:
* Handle binder died events in PieService correctly

Patch Set #10:
* Simplified locking
* SYSTEM_UI_FLAG_HIDE_NAVIGATION support
* Fixed ADW Lauchner bug
Pie controls: A new way of activation

Based on "Pie controls: Introducing a pie delivery service" this
commit binds the pie controls to the newly created pie service.

Patch Set #2:
* Fixed glitch when displaying the search panel at the lock
  screen.

Patch Set #5:
* Switch Position to com.android.internal.util.pie.Position
* Removed legacy and unused code

Patch Set #6:
* Fixed lock screen glitch, finally!

Patch Set #7:
* Rebase

Patch Set #9:
* Moved almost all of the pie logic to PieController

Patch Set #10:
* Remove window completely from WindowManager when not shown

Patch Set #13:
* Fixed Taichi's bug
* Removed observers in PieView

Patch Set #14 & #15:
* Rebase