Fix benchmark unit tests.

Add benchmark file dependency in tests instead of using hard-coded
path to bionic-benchmarks.

In addition, add a TEST_MAPPING file so the tests run when benchmark files change.

Test: All unit tests pass.
Test: Ran atest bionic-benchmarks-tests.
Change-Id: I95608f5b5e75d9d74930960a2431c9896b621ce8
diff --git a/benchmarks/Android.bp b/benchmarks/Android.bp
index 17d2d68..f31e127 100644
--- a/benchmarks/Android.bp
+++ b/benchmarks/Android.bp
@@ -154,7 +154,13 @@
         "libbase",
         "libBionicBenchmarksUtils",
     ],
-    data: ["test_suites/*"],
+    data: [
+        "test_suites/*",
+        "suites/*",
+        ":bionic-benchmarks",
+    ],
+    test_suites: ["device-tests"],
+    require_root: true,
 }
 
 cc_binary {