Change validate_event_shape's default value to False.

Improves the bijector's compatibility with `vectorized_map`.

PiperOrigin-RevId: 377204164

Author: Googler

tensorflow_probability/python/bijectors/chain.py

@@ -81,7 +81,7 @@ class Chain(composition.Composition):
   def __init__(self,
                bijectors=None,
                validate_args=False,
-               validate_event_size=True,
+               validate_event_size=False,
                parameters=None,
                name=None):
     """Instantiates `Chain` bijector.

tensorflow_probability/python/bijectors/chain_test.py

@@ -378,17 +378,23 @@ def testDofChangeError(self):
     smc = tfb.SoftmaxCentered()
 
     # Increase in event-size is the last step. No problems here.
-    safe_bij = tfb.Chain([smc, exp], validate_args=True)
+    safe_bij = tfb.Chain([smc, exp],
+                         validate_args=True,
+                         validate_event_size=True)
     self.evaluate(safe_bij.forward_log_det_jacobian([1., 2., 3.], 1))
 
     # Increase in event-size before Exp.
-    raise_bij = tfb.Chain([exp, smc], validate_args=True)
+    raise_bij = tfb.Chain([exp, smc],
+                          validate_args=True,
+                          validate_event_size=True)
     with self.assertRaisesRegex((ValueError, tf.errors.InvalidArgumentError),
                                 r".+degrees of freedom.+"):
       self.evaluate(raise_bij.forward_log_det_jacobian([1., 2., 3.], 1))
 
     # When validate_args is False, warns instead of raising.
-    warn_bij = tfb.Chain([exp, smc], validate_args=False)
+    warn_bij = tfb.Chain([exp, smc],
+                         validate_args=False,
+                         validate_event_size=True)
     with mock.patch.object(tf, "print", return_value=tf.no_op()) as mock_print:
       self.evaluate(warn_bij.forward_log_det_jacobian([1., 2., 3.], 1))
       print_args, _ = mock_print.call_args