sepolicy: restrict /vendor/app from most coredomains

The change makes 'vendor_app_file' accessible only to few platform
domains like dex2oat, idmap, installd, system_server and appdomain.

Bug: 36681210
Test: Boot sailfish (treble device) from wiped flashall
Test: Connect to wifi and launch chrome to load few websites.
Test: Launch camera and record + playback video

Change-Id: Ib8757fedbf2e19c8381c8cd0f8f2693b2345534b
Signed-off-by: Sandeep Patil <sspatil@google.com>