getAlpnSelectedProtocol android 15 changes

[VEZE]

This method marked as max-target-q on android 15 chagelog. Lcom/android/org/conscrypt/OpenSSLSocketImpl->getAlpnSelectedProtocol()[B,core-platform-api,max-target-q

Method may fall under the category of APIs that are conditionally blocked based on the target API level of the app. Specifically, if app targets a version higher than Android 10 (API level 29), we might encounter restrictions accessing this method due to non-SDK interface policies.

What version of gRPC-Java are you using?

1.66.0

What is your environment?

Android

What did you expect to see?

Nothing in strictMode logs.

What did you see instead?

Lcom/android/org/conscrypt/OpenSSLSocketImpl;->getAlpnSelectedProtocol()[B io.grpc.okhttp.internal.OptionalMethod.getPublicMethod (OptionalMethod.java:178)

Steps to reproduce the bug

Enabling strictMode with non sdk api violations logging.

    StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()
            .detectNonSdkApiUsage()
            .penaltyLog()
            .build());

[kannanjgithub]

In the android documentation for "Expected behavior when restricted non-SDK interfaces are accessed" it says "NoSuchMethodError" will be thrown for "Reflection using Class.getDeclaredMethod(), Class.getMethod()", which is handled and ignored in gRPC okhttp code. So it should be fine.

[ejona86]

But if GET_ALPN_SELECTED_PROTOCOL fails then it only tried NPN next, which should fail too. I think the question is why wasn't the [Java 9 ALPN API](https://docs.oracle.com/en/java/javase/21/docs/api/java.base/javax/net/ssl/SSLSocket.html#getApplicationProtocol()) used, or why did it fail. I see it was used on an earlier line, so it failed? OptionalMethod only does reflection when actually invoked, so it seems it was used.

The "Java 9 ALPN APIs" are only available on Android 10+, so if you targeted a newer version but your minSdk is lower and you were testing on an older device, that could be a problem. That would mean there is no ALPN API available at all.

@VEZE, what version of Android were you running on when you noticed this issue?

[VEZE]

@ejona86 Android 15

[kannanjgithub]

Do you find this log viz

Socket unsupported for getApplicationProtocol, will try old methods

with FINER logging enabled? Or alternatively,

Failed to find Android 10.0+ APIs

from here (which would be surprising).