Testing: SLES - GCloud SDK update needs sudo

[LujieDuan]

Description

For SLES 12 and 15, we download a versioned (453.0.0) tarball, and try to upgrade to the latest version to keep in sync with other platforms.
There is a new version of the SDK available today (454.0.0) and when call gcloud components update, the command failed because it requires sudo to actually apply the update.

Related issue

b/308605793

How has this been tested?

Integration tests to pass on SLES 12 and 15.

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.

[avilevy18]

LGTM