Allow system_server access to hidraw devices.

This allows AccessibilityManagerService in system_server to
interact with a HID-supported Braille Display.

Bug: 303522222
Test: ls -z /dev/hidraw0
Test: plat_file_contexts_test
Test: Open FileInputStream and FileOutputStream on this device
      path from AccessibilityManagerService
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:67a63cc046769759aa43cf1653f11e57c55cd1db)
Merged-In: I2982e907bd2a70c1e4e8161647d6efd65110b99c
Change-Id: I2982e907bd2a70c1e4e8161647d6efd65110b99c
diff --git a/private/file_contexts b/private/file_contexts
index 32092da..3cfbaf0 100644
--- a/private/file_contexts
+++ b/private/file_contexts
@@ -127,6 +127,7 @@
 /dev/fuse		u:object_r:fuse_device:s0
 /dev/gnss[0-9]+		u:object_r:gnss_device:s0
 /dev/graphics(/.*)?	u:object_r:graphics_device:s0
+/dev/hidraw[0-9]+	u:object_r:hidraw_device:s0
 /dev/hw_random		u:object_r:hw_random_device:s0
 /dev/hwbinder		u:object_r:hwbinder_device:s0
 /dev/input(/.*)?	u:object_r:input_device:s0