HERESUP-98784: RetryExecutor to close the response it abandons, releasing the connection

[Azbesciak]

HERESUP-98784

RetryExecutor never closes the response it abandons, so a pooled HttpProvider never gets that connection back. Once every connection for the route has leaked this way, the next attempt blocks on the connection-request timeout and the call fails with a pool timeout instead of the status the server sent.

HereAccessTokenProvider with a stock ApacheHttpClientProvider and Socket5xxExponentialRandomBackoffPolicy, against a server scripted 503, 503, 200: before, two requests, then ConnectionPoolTimeoutException after ~11 s. After, three requests and the token.

Affected: anyone passing a response-retrying policy to setRetryPolicy/withRetryPolicy, in 0.4.33 through 0.4.36. Callers on the NoRetryPolicy default are not.

The fix closes the abandoned response before the next attempt starts. The closed response stays in the RetryContext, so a policy sees exactly what it saw before, and the response handed back to the caller is never closed.

Apache's close() drains the body, so a 5xx whose body stalls now costs one read timeout before the retry. Against a server that sends a partial body then hangs, 8 ms became 5 s. Aborting instead is not reachable through HttpProvider.HttpResponse.

Also found, not fixed here

• Socket5xxExponentialRandomBackoffPolicy.shouldRetry: the getCause() instanceof SocketTimeoutException arm sits outside the maxNumberOfRetries check. A connect timeout arrives in that shape, so an unreachable endpoint retries without bound.
• getNextRetryIntervalMillis computes retryIntervalMillis * nextInt(1 << retryCount) in int: 0 ms on about half of first retries, negative from retryCount 22, IllegalArgumentException at 31.
• RetryExecutor swallows InterruptedException without restoring the interrupt flag.
• ApacheHttpClientProvider builds JSON bodies as a non-repeatable BasicHttpEntity, so a retried JSON-body request resends an empty body. Form-encoded requests, including the token endpoint, are fine.