Add micro-benchmark for media metrics

Test: this is it
Change-Id: I3762223eb5ca67757debba02245a2ad87dd7e75e
diff --git a/services/mediametrics/benchmarks/Android.bp b/services/mediametrics/benchmarks/Android.bp
new file mode 100644
index 0000000..b61f44f
--- /dev/null
+++ b/services/mediametrics/benchmarks/Android.bp
@@ -0,0 +1,6 @@
+cc_test {
+    name: "mediametrics_benchmarks",
+    srcs: ["mediametrics_benchmarks.cpp"],
+    shared_libs: ["libbinder", "libmediametrics",],
+    static_libs: ["libgoogle-benchmark"],
+}