[Partition] Set default strategy to obfuscated key with partitions

Change-Id: I2a9e9e963544cbc82a1f2f2a74ca3e712b8e00f5
diff --git a/src/main/java/com/android/tools/r8/retrace/internal/MappingPartitionKeyStrategy.java b/src/main/java/com/android/tools/r8/retrace/internal/MappingPartitionKeyStrategy.java
index 6b050c6..b3012cf 100644
--- a/src/main/java/com/android/tools/r8/retrace/internal/MappingPartitionKeyStrategy.java
+++ b/src/main/java/com/android/tools/r8/retrace/internal/MappingPartitionKeyStrategy.java
@@ -9,7 +9,8 @@
   OBFUSCATED_TYPE_NAME_AS_KEY(0),
   OBFUSCATED_TYPE_NAME_AS_KEY_WITH_PARTITIONS(1);
 
-  private static final MappingPartitionKeyStrategy DEFAULT_STRATEGY = OBFUSCATED_TYPE_NAME_AS_KEY;
+  private static final MappingPartitionKeyStrategy DEFAULT_STRATEGY =
+      OBFUSCATED_TYPE_NAME_AS_KEY_WITH_PARTITIONS;
 
   private final int serializedKey;