[CQ] Add v8_linux_shared_compile_rel to CQ

NOTRY=true

Bug: v8:6918, chromium:747960
Change-Id: I0a83cd1eebfe4082399dc1d26dbdf7ff3ef1f158
Reviewed-on: https://chromium-review.googlesource.com/731044Reviewed-by: Sergiy Byelozyorov <sergiyb@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48814}

infra/config/cq.cfg

@@ -29,7 +29,6 @@ verifiers {
       }
       builders {
         name: "v8_linux_shared_compile_rel"
-        experiment_percentage: 20
       }
       builders {
         name: "v8_win64_clang_compile_rel"