introduce binderRpcBenchmark

VRRRRRRRRRRRRRRRRRMMMMMMM!!!

Some caveats:
- we are partially benchmarking the scheduler
- this is a microbenchmark

Results running on host (we'll want to watch and tune these on real
devices with core clamping and thermal throttling off):

-------------------------------------------------------------
Benchmark                   Time             CPU   Iterations
-------------------------------------------------------------
BM_getRootObject        45959 ns        39054 ns        18345
BM_pingTransaction      26128 ns        23360 ns        28705
BM_repeatString        394286 ns       200186 ns         3508
BM_repeatBinder         39357 ns        37437 ns        17705

Bug: 182940634
Test: run benchmark on host and on cuttlefish
Change-Id: I5084a00ddf207eaeb803da98587ca04df65add4d
diff --git a/libs/binder/tests/Android.bp b/libs/binder/tests/Android.bp
index afc4b1b..e39408c 100644
--- a/libs/binder/tests/Android.bp
+++ b/libs/binder/tests/Android.bp
@@ -151,6 +151,22 @@
     require_root: true,
 }
 
+cc_benchmark {
+    name: "binderRpcBenchmark",
+    defaults: ["binder_test_defaults"],
+    host_supported: true,
+    srcs: [
+        "binderRpcBenchmark.cpp",
+        "IBinderRpcBenchmark.aidl",
+    ],
+    shared_libs: [
+        "libbase",
+        "libbinder",
+        "liblog",
+        "libutils",
+    ],
+}
+
 cc_test {
     name: "binderThroughputTest",
     defaults: ["binder_test_defaults"],