Revert "runas/shell.te: remove {kernel} to perf_event_open"

This reverts commit 6c9a13f387662128f4c984f253cd71aa0b1ce4dd.

Reason for revert: Droidmonitor created revert due to b/392093609. Will be verifying through ABTD before submission.

Change-Id: Ifdefd9d211686babb923ae62d0f5ece59bfd540a
diff --git a/private/shell.te b/private/shell.te
index 3e45e1f..2033f7e 100644
--- a/private/shell.te
+++ b/private/shell.te
@@ -142,7 +142,7 @@
 
 # Allow shell to call perf_event_open for profiling other shell processes, but
 # not the whole system.
-allow shell self:perf_event { open read write };
+allow shell self:perf_event { open read write kernel };
 
 # Allow shell to read microdroid vendor image
 r_dir_file(shell, vendor_microdroid_file)