Fail when an unpickle succeeds but has extra junk data at the end.

Also adds tests to ensure this is working.
2 jobs for dkasak/fix-unpickling-error-handling in 13 minutes and 15 seconds (queued for 32 seconds)
Child pipeline (parent)
Status Job ID Name Coverage
  Build
passed build:android:aar #24160
docker

00:07:45

 
  Test
passed test:android:aar #24163
docker

00:05:29