Revert "Disable test while investigating."

Change #195560 fixes the test.
This reverts commit 1c58d6980541eb469f4860f00a77ba8c729efef9.

Change-Id: Idbfb0c5d2fbc1796f7dd1056181b5fc912a065a3
diff --git a/tools/libcore_failures.txt b/tools/libcore_failures.txt
index 4699907..d11e015 100644
--- a/tools/libcore_failures.txt
+++ b/tools/libcore_failures.txt
@@ -248,10 +248,5 @@
           "org.apache.harmony.tests.java.util.prefs.AbstractPreferencesTest#testFlush",
           "org.apache.harmony.tests.java.util.prefs.AbstractPreferencesTest#testSync",
           "org.apache.harmony.tests.java.util.prefs.FilePreferencesImplTest#testPutGet"]
-},
-{
-  description: "Missing resource",
-  result: EXEC_FAILED,
-  names: ["libcore.java.util.LocaleTest#test_SerializationBug_26387905"]
 }
 ]