MCAP: Add a test tool for MCAP

* Add a command line tool for MCAP related tests
* This tool can access the Bluetooth stack via a command line program
* Type "help" to obtain a list of available console commands in this
  Bluetooth
* Bluetooth must be disabled when this tool is running

Bug: 37867299
Test: make, PTS MCAP test
Change-Id: I106e6625ee8a29b7fdad88cdfeb99419054ef771
diff --git a/BUILD.gn b/BUILD.gn
index 3cb29e1..618de1c 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -39,3 +39,10 @@
     "//device:net_test_device",
   ]
 }
+
+group("test_tools") {
+  testonly = true
+  deps = [
+    "//tools/mcap_tool:mcap_tool"
+  ]
+}