Add GPU tests for all distros on a single GPU model

[LujieDuan]

Description

Expand the testing coverage of the GPU receivers: originally only test all models on Focal; right now test one model (L4) on all supported distros.

Related issue

b/305709922

How has this been tested?

Added installation script for all distros and checked to make sure new tests passed.
(Add release tag to short circuit TestMinimumSupportedAgentVersionIsModified since the metadata file struct has been changed in this PR).

Checklist:

• Unit tests
  • Unit tests do not apply.
  • Unit tests have been added/modified and passed for this PR.
• Integration tests
  • Integration tests do not apply.
  • Integration tests have been added/modified and passed for this PR.
• Documentation
  • This PR introduces no user visible changes.
  • This PR introduces user visible changes and the corresponding documentation change has been made.
• Minor version bump
  • This PR introduces no new features.
  • This PR introduces new features, and there is a separate PR to bump the minor version since the last release already.
  • This PR bumps the version.