chore: bump Java and Gradle version in Android sample

[yq-yang-qin]

Description

• Bump Java and Gradle version in Android sample

General Checklist

• Added new tests to cover change, if needed
• Security oriented best practices and standards are followed (e.g. using input sanitization, principle of least privilege, etc)
• Documentation update for the change if required
• PR title conforms to conventional commit style
• If breaking change, documentation/changelog update with migration instructions

By submitting this pull request, I confirm that my contribution is made under the terms of the MIT-0 license.

[zhu-xiaowei]

For build-android actions, Please fix the build error:

error: invalid source release: 21

For the build-ios actions, Please update the runs-on parameter in
https://github.com/aws-samples/swift-chat/actions/runs/12339018149/workflow#L11,
https://github.com/aws-samples/clickstream-sdk-samples/blob/main/.github/workflows/build-rn.yml#L37
to macos-latest and try again.

[yq-yang-qin]

@zhu-xiaowei, thanks for the comment, I've successfully updated the Build for Android and Build for iOS workflow actions. However, my PR is now encountering issues in the Build for React Native workflow:

The build-ios action within the React Native workflow is failing with the error "Error installing boost: Verification checksum was incorrect". This is an open issue in the Boost package, requiring manual intervention to fix the checksum link in boost.podspec file.

The build-android action is failing due to a compileSdkVersion issue.

Given that my PR doesn't modify anything in the Clickstream React Native SDK example, and these failures are unrelated to my tests on the Android SDK, would it be acceptable to proceed with merging the PR despite these React Native action failures?

[zhu-xiaowei]

This PR indeed does not modify ReactNative code, it only makes changes to the Android Sample, I think this PR can be merged first.
Regarding the ReactNative build failures, they appear to be related to the GitHub action build environment upgrades of ubuntu-latest and macos-latest. Suggest fixing these issues in a new PR.