[benchmark][authfs] Add benchmarks for authfs random read

This CL does two things
- Add benchmarks for authfs random read;
- Measure the read time inside the VM.

Test: atest AuthFsBenchmarks AuthFsHostTests
Bug: 236123069
Change-Id: I470fe048645c6aced09b045a7f45251415bd9de8
diff --git a/authfs/tests/Android.bp b/authfs/tests/Android.bp
index b662bee..0177254 100644
--- a/authfs/tests/Android.bp
+++ b/authfs/tests/Android.bp
@@ -23,6 +23,7 @@
         ":authfs_test_files",
         ":CtsApkVerityTestPrebuiltFiles",
         ":MicrodroidTestApp",
+        ":measure_io",
     ],
 }
 
@@ -42,3 +43,13 @@
     test_suites: ["general-tests"],
     test_harness: false,
 }
+
+cc_binary {
+    name: "measure_io",
+    srcs: [
+        "measure_io.cpp",
+    ],
+    shared_libs: [
+        "libbase",
+    ],
+}