Add a new java_header_libs property that exports header jars (as
java_libs currently does) and switch java_libs to export implementation
jars instead.
Refactors implementation of the existing library sdk member type so
both properties can be supported from common code as they differ only
on the jar being exported.
Bug: 143678475
Test: m nothing
Change-Id: I04642122f72d083bbdfd3290624f957b71ee8875
Makes it easier for multiple people to work on different areas without
conflicts.
Bug: 143678475
Test: m conscrypt-module-sdk
Change-Id: I93140450c0b049946a9d0432225bccff82f5a873