ci: [WLEO-365] Add Android APK in release artifacts

[LazyAfternoons]

List of Changes

• Run fastlane init for the Android project;
• Update the .env.example with actual values;
• Add an action which builds the example app via Fastlane and creates a GitHub release with the resulting APK as asset. This action can be manually triggered and can bump the example app version following the semantic versioning convention. The library publish.yml workflow is now only executed if the release title doesn't contain example which is the name publish-app.yml assigns to the example app release. This avoid running the library publishing workflow when a release for the example is created.

Motivation and Context

This PR introduces a workflow which creates an example app release with an Android APK in its assets.
A new GitHub release is created by the aforementioned workflow with example in its title.
Changelogs are currently not generated as this requires an important refactor on how we tag commits and also on how the library release process is currently handled.

How Has This Been Tested?

This cannot be tested until merged.

Screenshots (if appropriate):

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[mastro993]

LGTM