Bump actions/checkout from v1 to v2.3.4 (#1)

Bumps [actions/checkout](/~https://github.com/actions/checkout) from v1 to v2.3.4.
- [Release notes](/~https://github.com/actions/checkout/releases)
- [Changelog](/~https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v1...5a4ac90)

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

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

.github/workflows/generate-apk.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2.3.4
       - name: set up JDK 1.8
         uses: actions/setup-java@v1
         with: