LibNativeBridge: Add early init & env setup

Add a method to set up /proc/cpuinfo with enough privileges. Set
up the environment for an app in InitializeNativeBridge().

Turn on -Wall for libnativebridge.

(cherry picked from commit 962eb40abb68eb60077da158755b6a09c306aa41)
(cherry picked from commit ab0da5a9a6860046619629b8e6b83692d35dff86)
(cherry picked from commit 2f71cb24fa16c0388591918f1354d1f8608cc6e5)
(cherry picked from commit 04054e28e24866d76034236843490829b80df40c)
(cherry picked from commit 4390a632366ecf89af5f6c0fed39baf9aab2d0f1)

Bug: 17671501
Change-Id: Id4f4127d82737b5e56a77175e1068ff5cea60f9d
7 files changed