Revert "Disable flaky LifecycleTest (Exe_TerminateProcess) on Fuchsia"

This reverts commit 06d88933.

Reason for revert: Flaking test has been refactored in such a way that
we believe it will no longer flake.  (Sheriffs: Please re-land the CL below if the test starts to flake again!)

Original change's description:
> Disable flaky LifecycleTest (Exe_TerminateProcess) on Fuchsia
> 
> TBR: jam@chromium.org
> Bug: 863166
> Change-Id: I9e31154c0ba8cdc5fff7af5130c8a06029a4bdaa
> Reviewed-on: https://chromium-review.googlesource.com/1136029
> Commit-Queue: Kim Paulhamus <kpaulhamus@chromium.org>
> Reviewed-by: Kim Paulhamus <kpaulhamus@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#574942}

TBR=kpaulhamus@chromium.org, rockot@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 863166
Change-Id: I7a816e991cccb0559dcf8e0a43c96920a933352b
Reviewed-on: https://chromium-review.googlesource.com/1140873Reviewed-by: Wez <wez@chromium.org>
Commit-Queue: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575742}

services/service_manager/tests/lifecycle/lifecycle_unittest.cc

@@ -12,7 +12,6 @@
 #include "base/memory/ptr_util.h"
 #include "base/process/process.h"
 #include "base/run_loop.h"
-#include "build/build_config.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "services/service_manager/public/cpp/identity.h"
 #include "services/service_manager/public/cpp/service_test.h"
@@ -398,12 +397,7 @@ TEST_F(LifecycleTest, Exe_GracefulQuit) {
   process.Terminate(9, true);
 }
 
-#if defined(OS_FUCHSIA)
-#define MAYBE_Exe_TerminateProcess DISABLED_Exe_TerminateProcess
-#else
-#define MAYBE_Exe_TerminateProcess Exe_TerminateProcess
-#endif
-TEST_F(LifecycleTest, MAYBE_Exe_TerminateProcess) {
+TEST_F(LifecycleTest, Exe_TerminateProcess) {
   base::Process process = LaunchProcess();
 
   test::mojom::LifecycleControlPtr lifecycle = ConnectTo(kTestExeName);