Add selinux rules for android.hardware.usb.gadget.IUsbGadget AIDL migration

Covers the rules needed for the default AIDL implementation.

10-26 10:22:42.408   448   448 I auditd  : type=1400 audit(0.0:95): avc: denied { read } for comm="android.hardwar" name="interrupts" dev="proc" ino=4026531995 scontext=u:r:hal_usb_gadget_default:s0 tcontext=u:object_r:proc_interrupts:s0 tclass=file permissive=0

Bug: 218791946
Test: reboot and check if AIDL service is running.

Signed-off-by: Ricky Niu <rickyniu@google.com>
Change-Id: I8bdab3a682398f3c7e825a8894f45af2a9b6c199
diff --git a/vendor/file_contexts b/vendor/file_contexts
index d6dc9bc..ab47b83 100644
--- a/vendor/file_contexts
+++ b/vendor/file_contexts
@@ -102,6 +102,7 @@
 /(vendor|system/vendor)/bin/hw/android\.hardware\.tv\.tuner-service\.example(-lazy)?  u:object_r:hal_tv_tuner_default_exec:s0
 /(vendor|system/vendor)/bin/hw/android\.hardware\.usb@1\.0-service            u:object_r:hal_usb_default_exec:s0
 /(vendor|system/vendor)/bin/hw/android\.hardware\.usb-service\.example        u:object_r:hal_usb_default_exec:s0
+/(vendor|system/vendor)/bin/hw/android\.hardware\.usb\.gadget-service\.example   u:object_r:hal_usb_gadget_default_exec:s0
 /(vendor|system/vendor)/bin/hw/android\.hardware\.usb\.gadget@1\.1-service    u:object_r:hal_usb_gadget_default_exec:s0
 /(vendor|system/vendor)/bin/hw/android\.hardware\.uwb-service                 u:object_r:hal_uwb_default_exec:s0
 /(vendor|system/vendor)/bin/hw/android\.hardware\.vibrator@1\.0-service       u:object_r:hal_vibrator_default_exec:s0