fix: REGAPIC fix socket timeout for wait calls (#1476)

wait() LRO calls may take 2+ minutes, while default read timeout was 20sec.

gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpRequestRunnable.java

@@ -54,6 +54,8 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import org.threeten.bp.Duration;
+import org.threeten.bp.Instant;
 
 /** A runnable object that creates and executes an HTTP request. */
 @AutoValue
@@ -115,6 +117,16 @@ HttpRequest createHttpRequest() throws IOException {
 
     HttpRequest httpRequest = buildRequest(requestFactory, url, jsonHttpContent);
 
+    Instant deadline = getHttpJsonCallOptions().getDeadline();
+    if (deadline != null) {
+      long readTimeout = Duration.between(Instant.now(), deadline).toMillis();
+      if (httpRequest.getReadTimeout() > 0
+          && httpRequest.getReadTimeout() < readTimeout
+          && readTimeout < Integer.MAX_VALUE) {
+        httpRequest.setReadTimeout((int) readTimeout);
+      }
+    }
+
     for (HttpJsonHeaderEnhancer enhancer : getHeaderEnhancers()) {
       enhancer.enhance(httpRequest.getHeaders());
     }