Hi, nice idea for the article, but you got some parts wrong:
1. Obfuscation doesn't give you any security. It minifies the code, so the app is smaller. It has no impact on security. Wanna have more secure code, use DexGuard.
2. You must not store API keys in your app. No matter where you keep it. Just don't.
3. SafetyNet is deprecated
4. Updating dependencies doesn't mean your source code is more secure. Most of the time it could add additional bugs rather then help you with something