Fix memory leak on render destroy

[kiryldz]

PRs must be submitted under the terms of our Contributor License Agreement CLA.
Fixes: #420

Pull request checklist:

• Briefly describe the changes in this PR.
• Include before/after visuals or gifs if this PR includes visual changes.
• Write tests for all new functionality. If tests were not written, please explain why.
• Add example if relevant.
• Document any changes to public APIs.
• Apply changelog label ('breaking change', 'bug 🪲', 'build', 'docs', 'feature 🍏', 'performance ⚡', 'testing 💯') or use the label 'skip changelog'
• Add an entry inside this element for inclusion in the mapbox-maps-android changelog: <changelog>Fix memory leak on render destroy.</changelog>.

Summary of changes

This PR fixes memory leak for texture view renderer. It also improves overall render thread management - in some situations some essential code was not executed before killing render thread.
Additionally tests were added for MapboxSurfaceHolderRenderer.

Visuals

After fix, surface view:

After fix, texture view:

[tobrun]