[Bug] Change the sepolicy name for exo_camera_injection

- Change the sepolicy name from platfrom_app to exo_app.
- Selinux avc log:
E/SELinux: avc:  denied  { find } for interface=vendor.google.exo_camera_injection::IExoCameraInjection sid=u:r:exo_app:s0:c248,c256,c512,c768 pid=11479 scontext=u:r:exo_app:s0:c248,c256,c512,c768 tcontext=u:object_r:hal_exo_camera_injection_hwservice:s0 tclass=hwservice_manager permissive=0

Bug: 184736718
Test: Verified exo_camera_injection provider service use cases function as expected; no denials.
Change-Id: I08887b8b6020cb7b3fb3da77cea9a1f453655bea
2 files changed