Use version 1.12.0 of plugin for sample apps

[0xnm]

What does this PR do?

After the release of 1.12.0 of Gradle Plugin we can reference it for the sample apps.

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)

[codecov-commenter]

Codecov Report

Merging #204 (f67b98f) into develop (6da3f11) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             develop     #204   +/-   ##
==========================================
  Coverage      85.88%   85.88%           
  Complexity       180      180           
==========================================
  Files             21       21           
  Lines            588      588           
  Branches          78       78           
==========================================
  Hits             505      505           
  Misses            55       55           
  Partials          28       28