Android sets both V8_OS_ANDROID and V8_OS_LINUX. For the Wasm trap
handler, the difference between these OSes matters.

BUG= chromium:701590

Change-Id: I5ae703a1d932c8a63e499ad39a057ad1871a2ab1
Reviewed-on: https://chromium-review.googlesource.com/455556
Commit-Queue: Eric Holk <eholk@chromium.org>
Commit-Queue: Brad Nelson <bradnelson@chromium.org>
Reviewed-by: Brad Nelson <bradnelson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43807}