2nd attempt in fixing sepolicy for shell+oatdump

aosp/2876742 changed the file context of oatdump from system_file to
oatdump_exec, which broke shell access on older platform versions. This
change fixes the issue by changing the file context back to system_file.
Also grant uprobestats rx_file_perms to system_file so it can execute
oatdump.

For now retain the label oatdump_exec to avoid build breakage.
b/352184398. The label will be removed once it's safe to do so.

Bug: 350628688
Test: m hello_uprobestats && hello_uprobestats
Change-Id: Ic34c2b7d70ce4f602a4d2cd223b5a86ee23f9b0e
diff --git a/private/uprobestats.te b/private/uprobestats.te
index f6dd906..2c5711f 100644
--- a/private/uprobestats.te
+++ b/private/uprobestats.te
@@ -16,7 +16,7 @@
 allow uprobestats sysfs_uprobe:dir { search };
 
 # Allow uprobestats to popen oatdump.
-allow uprobestats oatdump_exec:file rx_file_perms;
+allow uprobestats system_file:file rx_file_perms;
 
 # Allow uprobestats to write atoms to statsd
 unix_socket_send(uprobestats, statsdw, statsd)