Fix some cases when refresh rate switching didn't work/timed out (#901)

## Description
An attempt to fix #769

1. Always fetch the `DisplayManager` when switching refresh rates
2. Use the Activity context instead of Application context

### Related issues
Fixes #769

### Testing
I still haven't reproduced #769 myself, but this change works fine on my
shield + LG C2

## Screenshots
N/A

## AI or LLM usage
None

app/src/main/java/com/github/damontecres/wholphin/MainActivity.kt

@@ -409,7 +409,7 @@ class MainActivity : AppCompatActivity() {
         }
 
     fun changeDisplayMode(modeId: Int) {
-        lifecycleScope.launch(Dispatchers.Main + ExceptionHandler()) {
+        lifecycleScope.launch(Dispatchers.Main + ExceptionHandler(autoToast = true)) {
             val attrs = window.attributes
             if (attrs.preferredDisplayModeId != modeId) {
                 Timber.d("Switch preferredDisplayModeId to %s", modeId)

app/src/main/java/com/github/damontecres/wholphin/services/RefreshRateService.kt

@@ -28,21 +28,6 @@ class RefreshRateService
     constructor(
         @param:ApplicationContext private val context: Context,
     ) {
-        private val displayManager = context.getSystemService(Context.DISPLAY_SERVICE) as DisplayManager
-        private val display get() = displayManager.getDisplay(Display.DEFAULT_DISPLAY)
-
-        val supportedDisplayModes get() = display.supportedModes.orEmpty()
-
-        private val displayModes: List<DisplayMode> by lazy {
-            display.supportedModes
-                .orEmpty()
-                .map { DisplayMode(it) }
-                .sortedWith(
-                    compareByDescending<DisplayMode>({ it.physicalWidth * it.physicalHeight })
-                        .thenBy { it.refreshRateRounded },
-                )
-        }
-
         /**
          * Find the best display mode for the given stream and signal to change to it
          */
@@ -55,6 +40,18 @@ class RefreshRateService
                 Timber.v("Not switching either refresh rate nor resolution")
                 return@withContext
             }
+            val displayManager =
+                MainActivity.instance.getSystemService(Context.DISPLAY_SERVICE) as DisplayManager
+            val display = displayManager.getDisplay(Display.DEFAULT_DISPLAY)
+            val displayModes =
+                display.supportedModes
+                    .orEmpty()
+                    .map { DisplayMode(it) }
+                    .sortedWith(
+                        compareByDescending<DisplayMode>({ it.physicalWidth * it.physicalHeight })
+                            .thenBy { it.refreshRateRounded },
+                    )
+
             val currentDisplayMode = display.mode
             require(stream.type == MediaStreamType.VIDEO) { "Stream is not video" }
             val width = stream.width

app/src/main/java/com/github/damontecres/wholphin/ui/detail/DebugPage.kt

@@ -1,8 +1,10 @@
 package com.github.damontecres.wholphin.ui.detail
 
 import android.content.Context
+import android.hardware.display.DisplayManager
 import android.os.Build
 import android.util.Log
+import android.view.Display
 import androidx.compose.foundation.background
 import androidx.compose.foundation.focusable
 import androidx.compose.foundation.gestures.scrollBy
@@ -32,11 +34,11 @@ import androidx.lifecycle.viewModelScope
 import androidx.tv.material3.MaterialTheme
 import androidx.tv.material3.Text
 import com.github.damontecres.wholphin.BuildConfig
+import com.github.damontecres.wholphin.MainActivity
 import com.github.damontecres.wholphin.data.ItemPlaybackDao
 import com.github.damontecres.wholphin.data.ServerRepository
 import com.github.damontecres.wholphin.data.model.ItemPlayback
 import com.github.damontecres.wholphin.preferences.UserPreferences
-import com.github.damontecres.wholphin.services.RefreshRateService
 import com.github.damontecres.wholphin.ui.launchIO
 import com.github.damontecres.wholphin.ui.showToast
 import com.github.damontecres.wholphin.util.ExceptionHandler
@@ -60,13 +62,19 @@ class DebugViewModel
     constructor(
         val serverRepository: ServerRepository,
         val itemPlaybackDao: ItemPlaybackDao,
-        val refreshRateService: RefreshRateService,
         val clientInfo: ClientInfo,
         val deviceInfo: DeviceInfo,
     ) : ViewModel() {
         val itemPlaybacks = MutableLiveData<List<ItemPlayback>>(listOf())
         val logcat = MutableLiveData<List<LogcatLine>>(listOf())
 
+        val supportedModes by lazy {
+            val displayManager =
+                MainActivity.instance.getSystemService(Context.DISPLAY_SERVICE) as DisplayManager
+            val display = displayManager.getDisplay(Display.DEFAULT_DISPLAY)
+            display.supportedModes.orEmpty()
+        }
+
         init {
             viewModelScope.launchIO {
                 serverRepository.currentUser.value?.rowId?.let {
@@ -260,7 +268,7 @@ fun DebugPage(
                     "Model: ${Build.MODEL}",
                     "API Level: ${Build.VERSION.SDK_INT}",
                     "Display Modes:",
-                    *viewModel.refreshRateService.supportedDisplayModes,
+                    *viewModel.supportedModes,
                 ).forEach {
                     Text(
                         text = it.toString(),