System server: Allow get/setsched to hal_camera domain.

Much like audio, the camera HAL may need to have key threads running
in SCHED_FIFO or similar priority.  Allow system_server to raise
thread priority for camera HALs to make this possible.

Test: Video recording works, with EIS. No logspam about EIS failure.
Bug: 35389145
Change-Id: I1d92f9f10dc3aff22ce56b8b9cc57db043631919

private/system_server.te

@@ -108,6 +108,7 @@ allow system_server appdomain:process { getsched setsched };
 allow system_server audioserver:process { getsched setsched };
 allow system_server hal_audio:process { getsched setsched };
 allow system_server cameraserver:process { getsched setsched };
+allow system_server hal_camera:process { getsched setsched };
 allow system_server mediaserver:process { getsched setsched };
 allow system_server bootanim:process { getsched setsched };