Demo project needs to be updated

[lihenggui]

I got a compilation error:

Manifest merger failed : uses-sdk:minSdkVersion 23 cannot be smaller than version 24 declared in library [:api] C:\StudioProjects\Shizuku-API\api\build\intermediates\merged_manifest\debug\AndroidManifest.xml as the library might be using APIs not available in 23
	Suggestion: use a compatible library with a minSdk of at most 23,
		or increase this project's minSdk version to at least 24,
		or use tools:overrideLibrary="rikka.shizuku.api" to force usage (may lead to runtime failures)

[neobenedict]

Bump.