battery: fix battery_history avc denials

Bug: 160202146
Test: pixelstats read battery_history sucess
Change-Id: Iaeb1633deb8b8385f39c73e5885e86d163f1e432
diff --git a/vendor/google/pixelstats_vendor.te b/vendor/google/pixelstats_vendor.te
index 09169cc..9f3f892 100644
--- a/vendor/google/pixelstats_vendor.te
+++ b/vendor/google/pixelstats_vendor.te
@@ -1,3 +1,4 @@
 allow pixelstats_vendor sysfs_typec_info:dir search;
 allow pixelstats_vendor sysfs_typec_info:file r_file_perms;
 allow pixelstats_vendor sysfs_batteryinfo:file rw_file_perms;
+allow pixelstats_vendor battery_history_device:chr_file r_file_perms;