Indefinite blocks on NativeCrypto.SSL_do_handshake

We have user reports from Google Cloud Dataproc that threads/tasks would intermittently hang on NativeCrypto.SSL_do_handshake. There were some Java and native thread dumps shared in GoogleCloudDataproc/hadoop-connectors/issues/153, but we were unable to produce a solid reproduction so far.

Dataproc currently uses Conscrypt 1.4.2 on java-8-openjdk-amd64, and on the OS side we have heard from both Debian 9 (Debian-provided OpenJDK) and Debian 10 (AdoptOpenJDK). One user shared with GCP Support that they still saw the same hang even after manually updating to Conscrypt 2.4.0.

Below is an example of the thread dump.

```
"gcsfs-batch-helper-3912" #4130 daemon prio=5 os_prio=0 tid=0x00007f92a4040800 nid=0x3130 runnable [0x00007f9330815000]
java.lang.Thread.State: RUNNABLE
at org.conscrypt.NativeCrypto.SSL_do_handshake(Native Method)
at org.conscrypt.NativeSsl.doHandshake(NativeSsl.java:392)
at org.conscrypt.ConscryptFileDescriptorSocket.startHandshake(ConscryptFileDescriptorSocket.java:225)
at org.conscrypt.ConscryptFileDescriptorSocket.waitForHandshake(ConscryptFileDescriptorSocket.java:474)
at org.conscrypt.ConscryptFileDescriptorSocket.getOutputStream(ConscryptFileDescriptorSocket.java:461)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:465)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:558)
- locked <0x0000000651a1d8a8> (a sun.net.www.protocol.https.HttpsClient)
at sun.net.www.protocol.https.HttpsClient.(HttpsClient.java:264)
at sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:367)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:191)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1156)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1050)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:177)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:162)
at com.google.cloud.hadoop.repackaged.gcs.com.google.api.client.http.javanet.NetHttpRequest.execute(NetHttpRequest.java:104)
at com.google.cloud.hadoop.repackaged.gcs.com.google.api.client.http.HttpRequest.execute(HttpRequest.java:981)
at com.google.cloud.hadoop.repackaged.gcs.com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:419)
at com.google.cloud.hadoop.repackaged.gcs.com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:352)
at com.google.cloud.hadoop.repackaged.gcs.com.google.api.client.googleapis.services.AbstractGoogleClientRequest.execute(AbstractGoogleClientRequest.java:469)
at com.google.cloud.hadoop.repackaged.gcs.com.google.cloud.hadoop.gcsio.BatchHelper.execute(BatchHelper.java:175)
at com.google.cloud.hadoop.repackaged.gcs.com.google.cloud.hadoop.gcsio.BatchHelper.lambda$queue$0(BatchHelper.java:163)
at com.google.cloud.hadoop.repackaged.gcs.com.google.cloud.hadoop.gcsio.BatchHelper$$Lambda$96/631118845.call(Unknown Source)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
```