Use common prefix for benchmark names

Test: atest MicrodroidBenchmarks
Change-Id: I93ac22fb3b178bad14af8647151b2a66a74e8ec1
diff --git a/tests/benchmark/src/java/com/android/microdroid/benchmark/MicrodroidBenchmarks.java b/tests/benchmark/src/java/com/android/microdroid/benchmark/MicrodroidBenchmarks.java
index f236e47..5f52989 100644
--- a/tests/benchmark/src/java/com/android/microdroid/benchmark/MicrodroidBenchmarks.java
+++ b/tests/benchmark/src/java/com/android/microdroid/benchmark/MicrodroidBenchmarks.java
@@ -112,7 +112,7 @@
         assertThat(found).isTrue();
 
         Bundle bundle = new Bundle();
-        bundle.putInt("avf_perf/microdroid/minimum_required_memory", minimum);
+        bundle.putInt(METRIC_NAME_PREFIX + "minimum_required_memory", minimum);
         mInstrumentation.sendStatus(0, bundle);
     }