Shade conscrypt within the Dataflow legacy worker jar

org.conscrypt:conscrypt-openjdk:1.1.3:linux-x86_64 relies on JNI which can't be shaded away since the C code doesn't support automatically figuring out its post relocation path (like tcnative can).

There is support for building conscrypt with an additional prefix but this doesn't work well with shading since it requires every user who wants to shade to build their own copy.

jniutil.cc relies on JNI_JARJAR_PREFIX https://github.com/google/conscrypt/blob/e3c1c99b3e0c56849cb7150bb95dc211b0ad058c/common/src/jni/main/cpp/conscrypt/jniutil.cc#L62

Imported from Jira [BEAM-6136](https://issues.apache.org/jira/browse/BEAM-6136). Original Jira may contain additional context.
Reported by: lcwik.