btrpc: Added timing information for rpcs run in V23GoRunner.
btrpc: Added timing information for rpcs run in V23GoRunner.

Times for bt rpc seem to be around:
New connection rpc     2.766450015s.
Cached connection rpc  69.678236ms.

Change-Id: I2d41cecccef546243394db392bf0b3d68d9ff133

vanadium/go.jni,vanadium/go.jni