tree 27908be274ad7da94a5f5f5650cc485f0abe0710
parent 99b084b94f7bb5dc0039799b26069b9e19590eee
author “Adam <“guerrieri@google.com”> 1525878171 -0700
committer “Adam <“guerrieri@google.com”> 1525887737 -0700

Add bad gateway error to recognized retry cases.

Convert to a set of failure string and make retry backoff conform to
google standard.
Add additional logging to distinguish when we do not retry because it
is not a retry case (but it failed).

b/64988437

Change-Id: I1e86dde71623e2b1488c276809bab930e515599f