Log some debug info in case of install failures.

It took ~month to troubleshoot a P0 bug only because we never output anything.
+fail immediately if session is invalid

Bug: 287567070
Test: adb install-multi-package --staged com.google.android.configinfrastructure.apex
Change-Id: Id673fa51a3ab22c818a87aa01c8e7420ffb82448