sepolicy for boot_control HAL service

Bug: 31864052
Test: Logging confirms service runs on boot
Merged-In: I41e9e5c45d2d42886cdf7ff6d364e9e6e3df1ff4
Change-Id: I41e9e5c45d2d42886cdf7ff6d364e9e6e3df1ff4
Signed-off-by: Connor O'Brien <connoro@google.com>

private/file_contexts

@@ -222,6 +222,7 @@
 /system/bin/hw/wifi_hal_legacy   u:object_r:wifi_hal_legacy_exec:s0
 /system/fake-lib(64)?/libart.*   u:object_r:libart_file:s0
 /system/lib(64)?/libart.*        u:object_r:libart_file:s0
+/system/bin/hw/android.hardware.boot@1.0-service u:object_r:hal_boot_exec:s0
 /system/bin/hw/android.hardware.nfc@1.0-service   u:object_r:android_hardware_nfc_1_0_service_exec:s0
 /system/bin/hw/android.hardware.vibrator@1.0-service   u:object_r:android_hardware_vibrator_service_exec:s0
 /system/bin/hw/android.hardware.vr@1.0-service   u:object_r:android_hardware_vr_exec:s0

private/hal_boot.te

+# may be started by init
+init_daemon_domain(hal_boot)

public/hal_boot.te

+# boot_control subsystem
+type hal_boot, domain;
+type hal_boot_exec, exec_type, file_type;
+
+# hwbinder access
+hwbinder_use(hal_boot)
+
+# call into system_server process (callbacks)
+binder_call(hal_boot, system_server)

public/system_server.te

@@ -147,6 +147,7 @@ allow system_server surfaceflinger:unix_stream_socket { read write setopt };
 
 # Perform Binder IPC.
 binder_use(system_server)
+binder_call(system_server, hal_boot)
 binder_call(system_server, android_hardware_vibrator_service)
 binder_call(system_server, android_hardware_vr)
 binder_call(system_server, binderservicedomain)