Island: Modify error messages in EncryptionKey32Bytes

monkey/monkey_island/cc/server_utils/encryption/encryption_key_types.py

@@ -1,8 +1,9 @@
 class EncryptionKey32Bytes(bytes):
     def __init__(self, key: bytes):
         if not isinstance(key, bytes):
-            raise TypeError("Key is not of type `bytes`")
+            raise TypeError("'key' must be of type 'bytes'")
+
         if len(key) == 32:
             self.key = key
         else:
-            raise ValueError("Key size should be 32 bytes")
+            raise ValueError("'key' must be exactly 32 bytes")