Cloud Spanner and gax 1.45.0 are incompatible

[sduskis]

Cloud Spanner retry testing is blocking an upgrade to gax 1.45.0. This needs to be fixed, since other clients need the upgrade. See #5255

[olavloite]

Looks to be caused by the change made in googleapis/gax-java#712.

[olavloite]

The change mentioned above makes a slight behavioral change that caused the test cases to fail:

• In Gax 1.44: RetrySettings.Builder.setTotalTimeout(Duration.ofMillis(1000)).setRetryableCodes(ImmutableSet.of()) - Will never cause a timeout because there are no retryable codes.
• In Gax 1.45: RetrySettings.Builder.setTotalTimeout(Duration.ofMillis(1000)).setRetryableCodes(ImmutableSet.of()) - Will cause a timeout after 1000 milliseconds, but will never retry.

The total timeout for the test cases has been increased and the test cases pass.