Add bytes to cirq_google proto (#7201)

* Add bytes to cirq_google proto

- Adds bytes to the cirq_google Arg proto
- Adds hooks in arg_func_langs to serialize and
deserialize it.

* Changed bytes to b

Author: dstrain115

cirq-google/cirq_google/api/v2/program.proto

@@ -421,6 +421,7 @@ message ArgValue {
     RepeatedString string_values = 7;
     tunits.Value value_with_unit = 8;
     bool bool_value = 9;
+    bytes bytes_value = 10;
   }
 }
 

cirq-google/cirq_google/api/v2/program_pb2.py

@@ -133,6 +133,8 @@ def arg_to_proto(
         msg.arg_value.bool_value = bool(value)
     elif isinstance(value, FLOAT_TYPES):
         msg.arg_value.float_value = float(value)
+    elif isinstance(value, bytes):
+        msg.arg_value.bytes_value = value
     elif isinstance(value, str):
         msg.arg_value.string_value = value
     elif isinstance(value, (list, tuple, np.ndarray)):
@@ -291,6 +293,8 @@ def arg_from_proto(
             return [str(v) for v in arg_value.string_values.values]
         if which_val == 'value_with_unit':
             return tunits.Value.from_proto(arg_value.value_with_unit)
+        if which_val == 'bytes_value':
+            return bytes(arg_value.bytes_value)
         raise ValueError(f'Unrecognized value type: {which_val!r}')
 
     if which == 'symbol':

cirq-google/cirq_google/api/v2/program_pb2.pyi

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import base64
 import inspect
 from typing import Dict
 
@@ -55,6 +56,7 @@ def _json_format_kwargs() -> Dict[str, bool]:
     [
         (1.0, {'arg_value': {'float_value': 1.0}}),
         (1, {'arg_value': {'float_value': 1.0}}),
+        (b'abcdef', {'arg_value': {'bytes_value': base64.b64encode(b'abcdef').decode("ascii")}}),
         ('abc', {'arg_value': {'string_value': 'abc'}}),
         (True, {'arg_value': {'bool_value': True}}),
         ([True, False], {'arg_value': {'bool_values': {'values': [True, False]}}}),