selinux: Allow GPU vendor applications to access gpu config settings

Allowing read and write access will help to read gpu vendor
config setting from the adreno_config file and help to write
gpu snapshot dump to path /data/vendor/gpu.

Below is the avc denial, being addressed with this change.

comm.adrenotest: type=1400 audit(0.0:619): avc: denied
{ read } for name="esx_config.txt" dev="sda8" ino=525724
scontext=u:r:untrusted_app_25:s0:c512,c768 tcontext=
u:object_r:vendor_data_file:s0 tclass=file permissive=0

CRs-Fixed: 2217279
Change-Id: Ic8d984b41b64e519a1e0141e401f1b81887b821e