Fix crash on start in release due to WebView remote debug pref

[jpelgrom]

Summary

Fixes a crash on start in release builds on start after merging #6813 due to calling WebView.setWebContentsDebuggingEnabled not on the main thread, by moving this call to the main thread.

This doesn't seem to be an issue in debug builds, and also isn't a timing issue (removing BuildConfig.DEBUG from the condition or introducing artificial delays doesn't introduce the crash in debug).

The preference change in settings is already done on the main thread.

FATAL EXCEPTION: DefaultDispatcher-worker-3
Process: io.homeassistant.companion.android, PID: 5477
java.lang.RuntimeException: Toggling of Web Contents Debugging must be done on the UI thread
 at WV.y3.o(chromium-SystemWebViewGoogle6432.aab-stable-772713703:3)
 at WV.vf2.g(chromium-SystemWebViewGoogle6432.aab-stable-772713703:115)
 at com.android.webview.chromium.WebViewChromiumFactoryProvider$StaticsAdapter.setWebContentsDebuggingEnabled(chromium-SystemWebViewGoogle6432.aab-stable-772713703:33)
 at android.webkit.WebView.setWebContentsDebuggingEnabled(WebView.java:2032)
 at io.homeassistant.companion.android.HomeAssistantApplication$onCreate$1$1.invokeSuspend(HomeAssistantApplication.kt:115)
 at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:34)
 at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:100)
 at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:586)
 at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:807)
 at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:717)
 at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:704)
 Suppressed: kotlinx.coroutines.internal.DiagnosticCoroutineContextException: [StandaloneCoroutine{Cancelling}@6f4696, Dispatchers.IO]

Checklist

• New or updated tests have been added to cover the changes following the testing guidelines.
• The code follows the project's code style and best_practices.
• The changes have been thoroughly tested, and edge cases have been considered.
• Changes are backward compatible whenever feasible. Any breaking changes are documented in the changelog for users and/or in the code for developers depending on the relevance.

Screenshots

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Link to pull request in documentation repositories

n/a

Any other notes

[jpelgrom]

Chromium source for the crash says this function is essentially a no-op in debug: https://source.chromium.org/chromium/chromium/src/+/main:android_webview/glue/java/src/com/android/webview/chromium/SharedStatics.java;l=166;drc=875e15c94d995212867016abd2651d71f1c9f4b4

[Copilot]

Pull request overview

This PR fixes an app-start crash in release builds by ensuring WebView.setWebContentsDebuggingEnabled(...) is invoked on the main (UI) thread when initializing the global WebView remote debugging preference in HomeAssistantApplication.

Changes:

• Compute the effective WebView debugging flag (BuildConfig.DEBUG || pref) during app startup.
• Switch to Dispatchers.Main before calling WebView.setWebContentsDebuggingEnabled(...) to satisfy WebView’s threading requirement.