Add policies for system_server to delete fpdata folder

Bug: 26211308
Change-Id: I8fd2d14ea52d49a33e6cdbcdf90630eea89f7dd0

system_server.te

@@ -424,7 +424,9 @@ allow system_server sdcard_type:dir { getattr search };
 allow system_server mnt_expand_file:dir r_dir_perms;
 
 # Allow system process to relabel the fingerprint directory after mkdir
-allow system_server fingerprintd_data_file:dir {r_dir_perms relabelto};
+# and delete the directory and files when no longer needed
+allow system_server fingerprintd_data_file:dir { r_dir_perms remove_name rmdir relabelto write };
+allow system_server fingerprintd_data_file:file { getattr unlink };
 
 userdebug_or_eng(`
   # Allow system server to create and write method traces in /data/misc/trace.