Optimize startup by preventing whole screen recomposing twice

[mlykotom]

What I have done and why

I reworked the way how we set up the MainActivity wrt to theming and user settings.

This includes:

• reacting to uiMode config change (before, the whole activity would be recreated when theme changed)
• encapsulate the state logic into its class
• prevent calling enableEdgeToEdge twice with different settings

This way I can get rid of one whole-screen recomposition, which is ~12ms on a Pixel 6.

Do tests pass?

• Run local tests on DemoDebug variant: ./gradlew testDemoDebug
• Check formatting: ./gradlew --init-script gradle/init.gradle.kts spotlessApply

[github-actions]

Combined test coverage report

Overall Project	39.98% -0.25%	❌
Files changed	64.57%	🍏

Module	Coverage
data	59.65% -5.52%	❌
app	28.33% -0.25%	🍏

Files

Module	File	Coverage
data	ConnectivityManagerNetworkMonitor.kt	0% -60.65%	❌
app	MainActivityViewModel.kt	90.38% -9.62%	🍏
	UiExtensions.kt	81.93% -18.07%	🍏
	MainActivity.kt	81.83% -1.23%	🍏

[github-actions]

Combined test coverage report

Overall Project	40.01% -0.05%	🍏
Files changed	90.27%	🍏

Module	Coverage
app	28.33% -0.25%	🍏

Files

Module	File	Coverage
app	MainActivityViewModel.kt	90.38% -9.62%	🍏
	UiExtensions.kt	81.93% -18.07%	🍏
	MainActivity.kt	81.83% -1.23%	🍏

[github-actions]

Combined test coverage report

Overall Project	40.05% -0.06%	🍏
Files changed	89.58%	🍏

Module	Coverage
app	28.55% -0.28%	🍏

Files

Module	File	Coverage
app	MainActivityViewModel.kt	90.38% -9.62%	🍏
	UiExtensions.kt	81.93% -18.07%	🍏
	MainActivity.kt	81.82% -2.02%	🍏

[github-actions]

Combined test coverage report

Overall Project	40.02% -0.06%	🍏
Files changed	89.58%	🍏

Module	Coverage
app	28.55% -0.28%	🍏

Files

Module	File	Coverage
app	MainActivityViewModel.kt	90.38% -9.62%	🍏
	UiExtensions.kt	81.93% -18.07%	🍏
	MainActivity.kt	81.82% -2.02%	🍏