Allow snapuserd to write log files to /data/misc

snapuserd logs are important when OTA failures happen. To make debugging
easier, allow snapuserd to persist logs in /data/misc/snapuserd_logs ,
and capture these logs in bugreport.

Bug: 280127810
Change-Id: I49e30fd97ea143e7b9c799b0c746150217d5cbe0
diff --git a/private/file_contexts b/private/file_contexts
index b1c7508..bb86761 100644
--- a/private/file_contexts
+++ b/private/file_contexts
@@ -664,6 +664,7 @@
 /data/misc/vold(/.*)?           u:object_r:vold_data_file:s0
 /data/misc/update_engine(/.*)?  u:object_r:update_engine_data_file:s0
 /data/misc/update_engine_log(/.*)?  u:object_r:update_engine_log_data_file:s0
+/data/misc/snapuserd_log(/.*)?  u:object_r:snapuserd_log_data_file:s0
 /data/system/dropbox(/.*)?      u:object_r:dropbox_data_file:s0
 /data/system/heapdump(/.*)?     u:object_r:heapdump_data_file:s0
 /data/misc/trace(/.*)?          u:object_r:method_trace_data_file:s0