Handle test failure better

Send the VM's console & log to logcat; ditto the output produced by
the payload.

Fix some missing \n in the payload (we wait for the \n before sending
to logcat).

Abort instead of ignoring a failure to send onPayloadReady; this
causes the test to fail fast (and produce a tombstone!) rather than
waiting until the 5 minute timeout expires.

Bug: 232403335
Test: atest MicrodroidTests

Change-Id: Ia499e527d45cb1383e5db3faab3de7b09c9a8d04