Add intra-core API required by conscrypt

An initial set of methods that need to be visible in
the intra-core API surface for conscrypt to compile.

There's a fix in JavaLibrary.bp to the core-current-stubs-gen
target to stop files in openjdk_mmodule_extra_files showing
up in the core.current.stubs.

Bug: 110404540
Bug: 113148576
Test: build
Change-Id: I4bade4dac925cfcb14df9335918319be897ac50d
17 files changed