Add policy for CompOS APEX data files.

Grant access to odsign to read & delete pending key files. Eventually
we will grant the CompOS daemon write access.

Bug: 190166662
Test: Via odsign; no denials seen.
Change-Id: I6d3c3e5b2aec8ef65bd28cbb274d18263534ce66
diff --git a/private/file_contexts b/private/file_contexts
index 8e341de..779a37a 100644
--- a/private/file_contexts
+++ b/private/file_contexts
@@ -568,6 +568,7 @@
 /data/misc/a11ytrace(/.*)?      u:object_r:accessibility_trace_data_file:s0
 /data/misc/apexdata(/.*)?       u:object_r:apex_module_data_file:s0
 /data/misc/apexdata/com\.android\.art(/.*)?           u:object_r:apex_art_data_file:s0
+/data/misc/apexdata/com\.android\.compos(/.*)?        u:object_r:apex_compos_data_file:s0
 /data/misc/apexdata/com\.android\.permission(/.*)?    u:object_r:apex_system_server_data_file:s0
 /data/misc/apexdata/com\.android\.scheduling(/.*)?    u:object_r:apex_system_server_data_file:s0
 /data/misc/apexdata/com\.android\.wifi(/.*)?          u:object_r:apex_system_server_data_file:s0