Improve public api tracking

[KCeh]

Summary

To improve tracking of public API exposed by the libs I implemented 2 changes:

1. Add binary compatibility plugin https://github.com/Kotlin/binary-compatibility-validator
2. Enable Explicit API mode on lib modules

Changes

• Added binary compatibility plugin (disabled for sample app)
• Enabled Explicit API mode on lib modules

Type

• Feature: This pull request introduces a new feature.
• Bug fix: This pull request fixes a bug.
• Refactor: This pull request refactors existing code.
• Documentation: This pull request updates documentation.
• Other: This pull request makes other changes.

Additional information

• This pull request introduces a breaking change.

Description

We should keep track of public API for libs. With this changes tracking will be easier.

Checklist

• I have performed a self-review of my own code.
• I have tested my changes, including edge cases.
• I have added necessary tests for the changes introduced (if applicable).
• I have updated the documentation to reflect my changes (if applicable).

Additional notes