Shuffle installd Binder implementation around.

Instead of writing wrapper methods in InstalldNativeService.cpp,
this change shifts the Binder implementation over into the existing
commands.cpp file.  This will let us migrate all methods over, and
then perform one final file rename to InstalldNativeService.cpp.

The downside of this approach is that we no longer have a giant kill
switch to quickly switch back.

Moves the moveCompleteApp() method over to Binder.

Test: builds, boots, apps install fine
Bug: 13758960, 30944031
Change-Id: I53550e05bc2b65155c3de18424f67b1a95450a6f