Add sepolicy for contexthub HAL

Adding sepolicty for contexthub service.

Test: GTS tests pass.
Change-Id: I2576b8028d12a31151d7b7869679b853eb16c75e

private/file_contexts

@@ -231,6 +231,7 @@
 /system/lib(64)?/libart.*        u:object_r:libart_file:s0
 /system/bin/hw/android\.hardware\.audio@2\.0-service          u:object_r:hal_audio_default_exec:s0
 /system/bin/hw/android\.hardware\.boot@1\.0-service           u:object_r:hal_boot_exec:s0
+/system/bin/hw/android\.hardware\.contexthub@1\.0-service     u:object_r:hal_contexthub_default_exec:s0
 /system/bin/hw/android\.hardware\.dumpstate@1\.0-service      u:object_r:hal_dumpstate_default_exec:s0
 /system/bin/hw/android\.hardware\.graphics\.allocator@2\.0-service   u:object_r:hal_graphics_allocator_default_exec:s0
 /system/bin/hw/android\.hardware\.graphics\.composer@2\.1-service    u:object_r:hal_graphics_composer_default_exec:s0

private/hal_contexthub_default.te

+type hal_contexthub_default, hal_contexthub, domain;
+type hal_contexthub_default_exec, exec_type, file_type;
+
+init_daemon_domain(hal_contexthub_default)

public/attributes

@@ -130,3 +130,4 @@ attribute hal_thermal;
 attribute hal_vibrator;
 attribute hal_vr;
 attribute hal_wifi;
+attribute hal_contexthub;

public/hal_contexthub.te

+# hwbinder access
+hwbinder_use(hal_contexthub)
+
+# call into system_server process (callbacks)
+binder_call(hal_contexthub, system_server)

public/system_server.te

@@ -160,6 +160,7 @@ binder_service(system_server)
 # Perform HwBinder IPC.
 hwbinder_use(system_server)
 binder_call(system_server, hal_boot)
+binder_call(system_server, hal_contexthub)
 binder_call(system_server, hal_ir)
 binder_call(system_server, hal_light)
 binder_call(system_server, hal_memtrack)