change KeyringTraceFlag values to bitshifted ints to match other implementations

Author: mattsb42-aws

src/aws_encryption_sdk/identifiers.py

@@ -334,7 +334,7 @@ class KeyringTraceFlag(Enum):
     """KeyRing Trace actions."""
 
     WRAPPING_KEY_GENERATED_DATA_KEY = 1
-    WRAPPING_KEY_ENCRYPTED_DATA_KEY = 2
-    WRAPPING_KEY_DECRYPTED_DATA_KEY = 3
-    WRAPPING_KEY_SIGNED_ENC_CTX = 4
-    WRAPPING_KEY_VERIFIED_ENC_CTX = 5
+    WRAPPING_KEY_ENCRYPTED_DATA_KEY = 1 << 1
+    WRAPPING_KEY_DECRYPTED_DATA_KEY = 1 << 2
+    WRAPPING_KEY_SIGNED_ENC_CTX = 1 << 3
+    WRAPPING_KEY_VERIFIED_ENC_CTX = 1 << 4