Add libandroidicu as static lib in the VtsHalAudio

VtsHalAudio statically links libxml2.
libxml2 depends on libandroidicu now,
and it should statically links libandroidicu as well.

TODO: b/121468463 to remove ICU from VtsHalAudio

Bug: 117094880
Test: m checkbuild
Change-Id: I105e7ad1517ecf8780adfb730650e1ad82f65857