Add json key file support for acloud.

Also add an option to let acloud accept json key file path option.

Bug: 111601636
Test: unit test and manually
Change-Id: Idcdcd533018462d648229ae2c6e9d5b9626821b9
Merged-In: Ie5834e683634f82d6e84a76e027adfa91913c59a
diff --git a/internal/lib/base_cloud_client.py b/internal/lib/base_cloud_client.py
index 67e26b1..273e2bd 100755
--- a/internal/lib/base_cloud_client.py
+++ b/internal/lib/base_cloud_client.py
@@ -89,6 +89,10 @@
             retry_backoff_factor=cls.RETRY_BACKOFF_FACTOR,
             serviceName=cls.API_NAME,
             version=cls.API_VERSION,
+            # This is workaround for a known issue of some veriosn
+            # of api client.
+            # https://github.com/google/google-api-python-client/issues/435
+            cache_discovery=False,
             http=http_auth)
 
     @staticmethod