Make a11y node info parceling more robust

Fix a bug where a malformed Parceled representation
of an AccessibilityNodeInfo could be used to mess with
Bundles as they get reparceled.

Bug: 36491278
Test: Verified that POC no longer works, a11y cts still passes.
AOSP-Change-Id: I10f24747e3ab87d77cd1deba56db4526e3aa5441
(cherry picked from commit 687bb44b)
(cherry picked from commit 487d8697)

CVE-2017-0664

Change-Id: I1dfcc4af5112a372ede1608e10d956553436e8f2