snapshotctl better logging

Test: snapshotctl merge --log-to-file
Bug: 148818798
Change-Id: I0e9c8ebb6632a56670a566f7a541e52e0bd24b08
diff --git a/private/file_contexts b/private/file_contexts
index be1453a..e3dad7b 100644
--- a/private/file_contexts
+++ b/private/file_contexts
@@ -543,6 +543,7 @@
 /data/misc/recovery(/.*)?       u:object_r:recovery_data_file:s0
 /data/misc/shared_relro(/.*)?   u:object_r:shared_relro_file:s0
 /data/misc/sms(/.*)?            u:object_r:radio_data_file:s0
+/data/misc/snapshotctl_log(/.*)?      u:object_r:snapshotctl_log_data_file:s0
 /data/misc/stats-active-metric(/.*)? u:object_r:stats_data_file:s0
 /data/misc/stats-data(/.*)?     u:object_r:stats_data_file:s0
 /data/misc/stats-service(/.*)?  u:object_r:stats_data_file:s0