Remove default value for the coverage meta-data file

Change-Id: I91e3c08ae1136a2f8dab5087f58a1ac6e56692cf
diff --git a/jack/src/com/android/jack/coverage/CodeCoverageMetadataFileWriter.java b/jack/src/com/android/jack/coverage/CodeCoverageMetadataFileWriter.java
index 1e5a749..7098460 100644
--- a/jack/src/com/android/jack/coverage/CodeCoverageMetadataFileWriter.java
+++ b/jack/src/com/android/jack/coverage/CodeCoverageMetadataFileWriter.java
@@ -65,8 +65,7 @@
   public static final PropertyId<OutputStreamFile> COVERAGE_METADATA_FILE = PropertyId.create(
       "jack.coverage.metadata.file", "File where the coverage metadata will be emitted",
       new OutputStreamCodec(Existence.MAY_EXIST).allowStandardOutputOrError())
-      .requiredIf(Options.CODE_COVERVAGE.getValue().isTrue())
-      .addDefaultValue("coverage.em");
+      .requiredIf(Options.CODE_COVERVAGE.getValue().isTrue());
 
   private static final TypeAndMethodFormatter binaryFormatter =
       BinarySignatureFormatter.getFormatter();