This PS adds default values for chart values and resolves some issues
in python code that utilizes these values:
validation_connect_timeout: 20
validation_read_timeout: 300
deckhand_client_connect_timeout: 20
deckhand_client_read_timeout: 300
drydock_client_connect_timeout: 20
drydock_client_read_timeout: 300
Change-Id: Ic5b1920257859239613a3ce77134e6b05bd7e9dd