R8 warnings

I enabled r8 on my project and when running my app I got a message that said

> Missing classes detected while running R8. Please add the missing classes or apply additional keep rules that are generated in /Users/idle/dev/androidapp/app/build/outputs/mapping/appRelease/missing_rules.txt.

This file contained this:

-dontwarn org.bouncycastle.jsse.BCSSLParameters
-dontwarn org.bouncycastle.jsse.BCSSLSocket
-dontwarn org.bouncycastle.jsse.provider.BouncyCastleJsseProvider
-dontwarn org.conscrypt.Conscrypt$Version
-dontwarn org.conscrypt.Conscrypt
-dontwarn org.conscrypt.ConscryptHostnameVerifier
-dontwarn org.openjsse.javax.net.ssl.SSLParameters
-dontwarn org.openjsse.javax.net.ssl.SSLSocket
-dontwarn org.openjsse.net.ssl.OpenJSSE

This looks similar to this PR https://github.com/google/conscrypt/pull/1046 might be worth taking a look to see if these should be added directly to this lib?