[fuchsia] clean up third_party/fuchsia/BUILD.gn
[fuchsia] clean up third_party/fuchsia/BUILD.gn

Change-Id: I5c5f03ea5882592008d11e2819962e8781954ca2
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/1555833
Reviewed-by: Scott Graham <e134406e1863f3b48b0795831afac5c0595efb36@chromium.org>
Commit-Queue: Francois Rousseau <abdb75be6d92482eb3ea75e9341306a6fcc3aacd@google.com>

chromium/crashpad,chromium/crashpad,chromium/crashpad