Remove unnecessary HAL permissions

Comments indicate that these permissions are used to access already
open FDs. However, getattr of a directory is clearly not necessary
for that, search of system_data_file is already granted to domain
and following symlinks is clearly not needed for reading an already
open FD.

Bug: 34980020
Test: boot marlin. Test drm with google play movies, no related
    denials
Test: cts-tradefed run cts -m CtsMediaTestCases -t \
    android.media.cts.MediaCasTest
    5/6 tests fail with no related selinux denials. The same 5/6
    also fail in selinux permissive mode.
Change-Id: Ib4b9a1e18bdc479d656b2d64917bbc0358515525

public/hal_cas.te

@@ -10,9 +10,7 @@ allow hal_cas_server hidl_memory_hwservice:hwservice_manager find;
 get_prop(hal_cas, serialno_prop)
 
 # Read files already opened under /data
-allow hal_cas system_data_file:dir { search getattr };
 allow hal_cas system_data_file:file { getattr read };
-allow hal_cas system_data_file:lnk_file r_file_perms;
 
 # Read access to pseudo filesystems
 r_dir_file(hal_cas, cgroup)

public/hal_drm.te

@@ -19,9 +19,7 @@ allow hal_drm system_file:file r_file_perms;
 allow hal_drm system_file:lnk_file r_file_perms;
 
 # Read files already opened under /data
-allow hal_drm system_data_file:dir { search getattr };
 allow hal_drm system_data_file:file { getattr read };
-allow hal_drm system_data_file:lnk_file r_file_perms;
 
 # Read access to pseudo filesystems
 r_dir_file(hal_drm, cgroup)