Revert "Re-enable test on Android."

This reverts commit cc361a9d.

Reason for revert: The test is flaky.
See https://bugs.chromium.org/p/chromium/issues/detail?id=1071110#c9

Original change's description:
> Re-enable test on Android.
> 
> This test was disabled for flakiness; however, over 500 attempts to
> reproduce the sync-related flakes were unsuccessful.
> 
> We suspect that the underlying problem has now been resolved.
> 
> See crrev/c/2150232 to view the attempts and the bug for more details.
> 
> Bug: 1071110
> Change-Id: Ib2364be94c17dc7c70b06950113594254e256287
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2165845
> Commit-Queue: Caitlin Fischer <caitlinfischer@google.com>
> Commit-Queue: Alexei Svitkine <asvitkine@chromium.org>
> Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#762482}

TBR=asvitkine@chromium.org,caitlinfischer@google.com

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

Bug: 1071110
Change-Id: Ife1f22bc58bee23d1e7664b24538b118e7316ca8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2167754Reviewed-by: Arthur Sonzogni <arthursonzogni@chromium.org>
Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#762775}

chrome/browser/metrics/metrics_service_user_demographics_browsertest.cc

@@ -13,6 +13,7 @@
 #include "base/memory/weak_ptr.h"
 #include "base/test/metrics/histogram_tester.h"
 #include "base/time/time.h"
+#include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/metrics/chrome_metrics_service_accessor.h"
 #include "chrome/browser/metrics/chrome_metrics_services_manager_client.h"
@@ -93,8 +94,15 @@ class MetricsServiceUserDemographicsBrowserTest
 // Keep this test in sync with testUMADemographicsReportingWithFeatureEnabled
 // and testUMADemographicsReportingWithFeatureDisabled in
 // ios/chrome/browser/metrics/demographics_egtest.mm.
+#if defined(OS_ANDROID)
+#define MAYBE_AddSyncedUserBirthYearAndGenderToProtoData \
+  DISABLED_AddSyncedUserBirthYearAndGenderToProtoData
+#else
+#define MAYBE_AddSyncedUserBirthYearAndGenderToProtoData \
+  AddSyncedUserBirthYearAndGenderToProtoData
+#endif
 IN_PROC_BROWSER_TEST_P(MetricsServiceUserDemographicsBrowserTest,
-                       AddSyncedUserBirthYearAndGenderToProtoData) {
+                       MAYBE_AddSyncedUserBirthYearAndGenderToProtoData) {
   test::DemographicsTestParams param = GetParam();
 
   base::HistogramTester histogram;