Put VM log to the system log

MicrodroidHostTestCases now uses the new "--log" option to save console
output from the VM to a file. Then the file is redirected to the system
log in background. That allows us to see what was happening inside
microdroid when it crashes during booting.

Bug: 191613547
Test: atest MicrodroidHostTestCases and see the device logcat. It has
log from the VM.

Change-Id: I153c64acdf46da23b0b1f3d35e32d7a6664661eb
1 file changed