Rename "user key" methods in vold

Rename methods that refer to "user key" to be more precise about what
they mean.  For more details, see the corresponding frameworks/base
changes (I202ebbfd2b4f79fedb3ed120a8ad81500c126894 and
I5894beb97823dced5954e405d779fada49c79e8d).

No change in behavior except for some changed log messages.

Flag: exempt, mechanical refactoring only
Test: presubmit
Change-Id: I9edcb557172395f4f6cf8e837efcc06fcfefb37d
diff --git a/FsCrypt.h b/FsCrypt.h
index 8d84bdc..f5c367c 100644
--- a/FsCrypt.h
+++ b/FsCrypt.h
@@ -23,14 +23,14 @@
 
 bool fscrypt_init_user0();
 extern bool fscrypt_init_user0_done;
-bool fscrypt_vold_create_user_key(userid_t user_id, int serial, bool ephemeral);
-bool fscrypt_destroy_user_key(userid_t user_id);
-bool fscrypt_set_user_key_protection(userid_t user_id, const std::string& secret);
+bool fscrypt_create_user_keys(userid_t user_id, int serial, bool ephemeral);
+bool fscrypt_destroy_user_keys(userid_t user_id);
+bool fscrypt_set_ce_key_protection(userid_t user_id, const std::string& secret);
 void fscrypt_deferred_fixate_ce_keys();
 
 std::vector<int> fscrypt_get_unlocked_users();
-bool fscrypt_unlock_user_key(userid_t user_id, int serial, const std::string& secret);
-bool fscrypt_lock_user_key(userid_t user_id);
+bool fscrypt_unlock_ce_storage(userid_t user_id, int serial, const std::string& secret);
+bool fscrypt_lock_ce_storage(userid_t user_id);
 
 bool fscrypt_prepare_user_storage(const std::string& volume_uuid, userid_t user_id, int serial,
                                   int flags);