chore(dependencies): general update of dependencies

[kikoso]

The current Pull Request introduces a general update of dependencies, and supersedes all the existing dependabot PRs.

This PR affecs the demo-java, demo-kotlin and snippets projects.

• Increased compileSdkVersion.
• Increased targetSdkVersion.
• Moves namespace from AndroidManifest to the build.gradle file.
• Increases Gradle plugin version.
• General dependencies updated.

This supersedes all the existing dependabot PRs:

#447, #446,#445,#444,#443,#441,#440,#439,#438,#437,#436,#435,#433,#431,#430,#429,#420,#419,#418,#416,#415,#401,#397,#396,#395,#394,#379 and #378.