ci: bump actions/cache from v2 to v2.1.4 (#336)

Bumps [actions/cache](https://github.com/actions/cache) from v2 to v2.1.4.
- [Release notes](https://github.com/actions/cache/releases)
- [Commits](https://github.com/actions/cache/compare/v2...26968a09c0ea4f3e233fdddbafd1166051a095f6)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/app-test.yaml

@@ -19,7 +19,7 @@ jobs:
           distribution: 'adopt'
           java-version: 11
       - name: Setup Gradle cache
-        uses: actions/cache@v2
+        uses: actions/cache@v2.1.4
         with:
           path: |
             ~/.gradle/caches