Permissions for input_native_boot flags

For input experiments that are enabled at boot time, allow system_server
to read and write the device config flags.

Bug: 120794829
Test: presubmit
Change-Id: I0f075a7579c593d4e07c3e31be529e34554068a6
diff --git a/private/property_contexts b/private/property_contexts
index 80ccbdf..d7563bc 100644
--- a/private/property_contexts
+++ b/private/property_contexts
@@ -169,6 +169,7 @@
 # Properties that relate to server configurable flags
 device_config.reset_performed           u:object_r:device_config_reset_performed_prop:s0
 persist.device_config.attempted_boot_count        u:object_r:device_config_boot_count_prop:s0
+persist.device_config.input_native_boot. u:object_r:device_config_input_native_boot_prop:s0
 persist.device_config.netd_native.           u:object_r:device_config_netd_native_prop:s0
 
 apexd.                  u:object_r:apexd_prop:s0