sepolicy: restrict access for /vendor/framework.

/vendor/framework is now designated location for vendor's platform
libraries. The directory is thus only made available for 'dex2oat'
coredomain.

Bug: 36680116
Test: Boot sailfish & angler and launch gApps, dialer w/ no denials for
      'vendor_framework_file'

Change-Id: I24c2ec30f836330005a972ae20d839bef9dcb8aa
Signed-off-by: Sandeep Patil <sspatil@google.com>