Give zygote execute access to ashmem

Change-Id: Ie667f87a1facacb5df842697660bc58ca73336f8
Fix the theme manager's context lookup

Since it has a specific non-app UID, context lookup was failing and
resulting in random behaviors, especially during app installs:

E/SELinux ( 3170): seapp_context_lookup:  No match for app with uid 1300, seinfo release, name com.tmobile.thememanager

Change-Id: Iaf1bb1b3ef9664db150896a29fc52df2ae5b3a4e