Test automation fixes

[nwmac]

This PR:

• Fixes backend build scripts to allow spaces in Stratos path
• Improves reliability of a couple of e2e tests
• Removes a spurious sleep in e2e test
• Ensures nightly AIO container is cleaned up in automated tests

[cfdreddbot]

Hey nwmac!

Thanks for submitting this pull request! I'm here to inform the recipients of the pull request that you and the commit authors have already signed the CLA.

[codecov]

Codecov Report

Merging #3073 into v2-master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           v2-master    #3073   +/-   ##
==========================================
  Coverage      71.01%   71.01%           
==========================================
  Files            607      607           
  Lines          26258    26258           
  Branches        5940     5940           
==========================================
  Hits           18648    18648           
  Misses          7610     7610