Fix Conscrypt NPE workaround

[PhilGlass]

After turning on HTTPS with MockWebServer 4.9.2 we started seeing the transient ssl == null failure described in #5587 on older emulators.

#5590 attempted to fix the problem, but I don't think the catch it introduced will ever be hit because the problematic NPE is wrapped in an InvocationTargetException:

11-05 11:53:36.557  5607 23163 E AndroidRuntime: FATAL EXCEPTION: MockWebServer
11-05 11:53:36.557  5607 23163 E AndroidRuntime: Process: com.xxx.xxx.xxx, PID: 5607
11-05 11:53:36.557  5607 23163 E AndroidRuntime: java.lang.AssertionError: java.lang.reflect.InvocationTargetException
11-05 11:53:36.557  5607 23163 E AndroidRuntime: 	at okhttp3.internal.platform.android.AndroidSocketAdapter.a(SourceFile:86)
11-05 11:53:36.557  5607 23163 E AndroidRuntime: 	at okhttp3.internal.platform.AndroidPlatform.b(SourceFile:86)
11-05 11:53:36.557  5607 23163 E AndroidRuntime: 	at okhttp3.mockwebserver.MockWebServer$SocketHandler.handle(MockWebServer.kt:516)
11-05 11:53:36.557  5607 23163 E AndroidRuntime: 	at okhttp3.mockwebserver.MockWebServer$serveConnection$$inlined$execute$1.run(Util.kt:580)
11-05 11:53:36.557  5607 23163 E AndroidRuntime: 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
11-05 11:53:36.557  5607 23163 E AndroidRuntime: 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
11-05 11:53:36.557  5607 23163 E AndroidRuntime: 	at java.lang.Thread.run(Thread.java:764)
11-05 11:53:36.557  5607 23163 E AndroidRuntime: Caused by: java.lang.reflect.InvocationTargetException
11-05 11:53:36.557  5607 23163 E AndroidRuntime: 	at java.lang.reflect.Method.invoke(Native Method)
11-05 11:53:36.557  5607 23163 E AndroidRuntime: 	at okhttp3.internal.platform.android.AndroidSocketAdapter.a(SourceFile:81)
11-05 11:53:36.557  5607 23163 E AndroidRuntime: 	... 6 more
11-05 11:53:36.557  5607 23163 E AndroidRuntime: Caused by: java.lang.NullPointerException: ssl == null
11-05 11:53:36.557  5607 23163 E AndroidRuntime: 	at com.android.org.conscrypt.NativeCrypto.getApplicationProtocol(Native Method)
11-05 11:53:36.557  5607 23163 E AndroidRuntime: 	at com.android.org.conscrypt.NativeSsl.getApplicationProtocol(NativeSsl.java:568)
11-05 11:53:36.557  5607 23163 E AndroidRuntime: 	at com.android.org.conscrypt.ConscryptFileDescriptorSocket.getApplicationProtocol(ConscryptFileDescriptorSocket.java:1085)
11-05 11:53:36.557  5607 23163 E AndroidRuntime: 	at com.android.org.conscrypt.OpenSSLSocketImpl.getAlpnSelectedProtocol(OpenSSLSocketImpl.java:134)
11-05 11:53:36.557  5607 23163 E AndroidRuntime: 	... 8 more

[yschimke]

@PhilGlass ughhhh.... and thanks. The folly of trying to fix an exception you haven't been able to reproduce.

Have you completed the CLA https://github.com/square/okhttp/blob/master/CONTRIBUTING.md

[yschimke]

Would a fix on 4.9.4 be required (our live release branch)? How urgent is this for you?

[PhilGlass]

I've filled in the CLA.

For our use case it's not super urgent, because we can work around it by forcing HTTP 1.1 (with protocolNegotiationEnabled = false) which bypasses that code path. But if there's going to be a 4.9.4 I don't see any harm in including it!

[swankjesse]

Thanks!