modem_diagnostics: add rules for getting battery info

Original change: https://android-review.googlesource.com/c/device/google/redbull-sepolicy/+/1881159

Bug: 204961005

Merged-In: I1fc134913db3c9248811a42ee1f37928f440c156
Change-Id: I1fc134913db3c9248811a42ee1f37928f440c156
(cherry picked from commit ae4b7183afd2b7cda3d6bfde7122a1d536e09426)
diff --git a/vendor/google/modem_diagnostics.te b/vendor/google/modem_diagnostics.te
index 4e7f3d5..c481738 100644
--- a/vendor/google/modem_diagnostics.te
+++ b/vendor/google/modem_diagnostics.te
@@ -18,4 +18,7 @@
   set_prop(modem_diagnostic_app, vendor_modem_diag_prop)
   set_prop(modem_diagnostic_app, radio_control_prop)
   set_prop(modem_diagnostic_app, vendor_radio_prop)
+
+  allow modem_diagnostic_app sysfs_batteryinfo:file r_file_perms;
+  allow modem_diagnostic_app sysfs_batteryinfo:dir search;
 ')