meson_to_hermetic: fix hermetic glslangValidator for soong

glslangValidator is invoked during the translation phase,
and since we no longer rely on the system binary, we must
have the hermetic version available for android too.

Bug: 481995008
Change-Id: I60315531bef457ef212a22f3300b13b7d1a97576
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/mesa/+/1547521
Reviewed-by: David Gilhooley <dgilhooley@google.com>
Commit-Queue: Craig Stout <cstout@google.com>