Fix keras BUILD file and add error checking. (#3492)

Fixes a bug that crept into a merge, and adds error checking to
prevent similar bugs from popping up.
diff --git a/integrations/tensorflow/e2e/iree_e2e_cartesian_product_test_suite.bzl b/integrations/tensorflow/e2e/iree_e2e_cartesian_product_test_suite.bzl
index e7a4fe5..0af8da8 100644
--- a/integrations/tensorflow/e2e/iree_e2e_cartesian_product_test_suite.bzl
+++ b/integrations/tensorflow/e2e/iree_e2e_cartesian_product_test_suite.bzl
@@ -141,6 +141,12 @@
         for failing_configuration in failing_configurations:
             failing_configuration = _normalize_dictionary(failing_configuration)
 
+            for key in failing_configuration:
+                if key not in flags_to_values:
+                    fail("Encountered unexpected key \"{}\" ".format(key) +
+                         "in a failing configuration. Expected one of " +
+                         "{}.".format(list(flags_to_values.keys())))
+
             # If a flag isn't specified in the failing configuration, assume it
             # is failing for all values of that flag.
             for key, values in flags_to_values.items():
diff --git a/integrations/tensorflow/e2e/keras/BUILD b/integrations/tensorflow/e2e/keras/BUILD
index ba2e090..0643127 100644
--- a/integrations/tensorflow/e2e/keras/BUILD
+++ b/integrations/tensorflow/e2e/keras/BUILD
@@ -295,14 +295,13 @@
                 "InceptionResNetV2",
                 "InceptionV3",
             ],
-            "datasets": ["imagenet"],
-            "backends": [
+            "target_backends": [
                 "iree_vulkan",
             ],
         },
         {
             # Failing llvm and vulkan:
-            "models": [
+            "model": [
                 "NASNetLarge",
                 "NASNetMobile",
                 "ResNet50V2",