add test for bytearray.startswith tuple

Author: timfel

graalpython/com.oracle.graal.python.test/src/tests/test_bytes.py

@@ -442,6 +442,8 @@ def test_startswith():
     assert b.startswith(b"h")
     assert not b.startswith(b"hellow")
     assert not b.startswith(b"ha")
+    assert b.startswith((b"hellow", b"he"))
+    assert not b.startswith((b"hellow", b"ha"))
 
 
 def test_endswith():