Adding a known issue for drag/drop cts tests in DR.

Drag/Drop tests built from nyc-mr1-dev won't pass
in nyc-dr1-dev because nyc-dr1-dev haven't picked up
the fix for the "drag/drop black hole" bug.

Bug: 31469490
Change-Id: I78394685cd72b9bc78ac90cb32f206fed53c1ee7
diff --git a/tools/cts-tradefed/res/config/cts-known-failures.xml b/tools/cts-tradefed/res/config/cts-known-failures.xml
index e7b08cb..84528d5 100644
--- a/tools/cts-tradefed/res/config/cts-known-failures.xml
+++ b/tools/cts-tradefed/res/config/cts-known-failures.xml
@@ -207,6 +207,9 @@
     <option name="compatibility:exclude-filter" value="CtsUsageStatsTestCases android.app.usage.cts.UsageStatsTest#testPackageUsageStatsIntervals" />
     <option name="compatibility:exclude-filter" value="CtsUsageStatsTestCases android.app.usage.cts.UsageStatsTest#testUsageEventsParceling" />
 
+    <!-- b/31469490 -->
+    <option name="compatibility:exclude-filter" value="CtsViewTestCases android.view.cts.DragDropTest" />
+
     <!-- b/23238984 -->
     <option name="compatibility:exclude-filter" value="CtsVoiceSettingsTestCases android.voicesettings.cts.ZenModeTest#testAll" />