HwBinder: log exceptions from Java

Before, if there was an uncaught exception from a Java HIDL server,
'Uncaught Exception!' would be printed in logcat, but the actual
exception would only be written to stderr. Now, we use the same binder
functionality to print the error to stdout.

Bug: N/A
Test: manual
Change-Id: I850c3158bad7313013f5e688850ec72cfa2fa686