[Sheriff] Disable NightLightTest.TestCustomScheduleGeopositionChanges.

This test start failing on multiple linux chrome os bots since 8th
March. There is no CL on the blame list that looks suspecious. Disable
the test and file a bug for the owner to look at it.

BUG=1059626
TBR=afakhry@chromium.org

Change-Id: I74770b256c9d6448d7cd3f581f44e8170b3828f3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2094416Reviewed-by: Maggie Cai <mxcai@chromium.org>
Commit-Queue: Maggie Cai <mxcai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#748091}

ash/system/night_light/night_light_controller_unittest.cc

@@ -721,7 +721,9 @@ TEST_F(NightLightTest, TestSunsetSunriseGeoposition) {
 // schedule setting. Current time is simulated to be updated accordingly. The
 // current time change should bring the controller into or take it out of the
 // night light mode accordingly if necessary, based on the settings.
-TEST_F(NightLightTest, TestCustomScheduleGeopositionChanges) {
+
+// Failed on 5 linux chromeos builds. http://crbug.com/1059626
+TEST_F(NightLightTest, DISABLED_TestCustomScheduleGeopositionChanges) {
   constexpr int kCustom_Start = 19 * 60;
   constexpr int kCustom_End = 2 * 60;