modem_diagnostics: add rules for getting battery info

Original change: https://android-review.googlesource.com/c/device/google/coral-sepolicy/+/1879629

Bug: 204961005

Merged-In: Ib9e0c1c1997d4cb4e5d15144f7a0076407286d09
Change-Id: Ib9e0c1c1997d4cb4e5d15144f7a0076407286d09
(cherry picked from commit bf7b34d672581aa159d27109f936308fea0efb42)
diff --git a/vendor/google/modem_diagnostics.te b/vendor/google/modem_diagnostics.te
index 7ba76de..d0151c8 100644
--- a/vendor/google/modem_diagnostics.te
+++ b/vendor/google/modem_diagnostics.te
@@ -21,4 +21,7 @@
 
   set_prop(modem_diagnostic_app, vendor_modem_diag_prop)
   set_prop(modem_diagnostic_app, radio_control_prop)
+
+  allow modem_diagnostic_app sysfs_batteryinfo:file r_file_perms;
+  allow modem_diagnostic_app sysfs_batteryinfo:dir search;
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