a11y: Make isTalkbackActive() live.

We made the assumption that the user needs to navigate to the setting to enable or disable the talkback, but there is a way to add a talkback switch on the bottom navigation bar. So the talkback can be enabled/disabled when the application is resumed. Since the UI may render differently depending on the talkback state, we need to make the composable `isTalkbackActive()` backed on a mutable state.

libraries/ui-utils/src/main/kotlin/io/element/android/libraries/ui/utils/time/IsTalkbackEnabled.kt

@@ -9,12 +9,26 @@ package io.element.android.libraries.ui.utils.time
 
 import android.view.accessibility.AccessibilityManager
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.platform.LocalContext
 
 @Composable
 fun isTalkbackActive(): Boolean {
     val context = LocalContext.current
     val accessibilityManager = remember { context.getSystemService(AccessibilityManager::class.java) }
-    return accessibilityManager.isTouchExplorationEnabled
+    var isTouchExplorationEnabled by remember { mutableStateOf(accessibilityManager.isTouchExplorationEnabled) }
+    DisposableEffect(Unit) {
+        val listener = AccessibilityManager.TouchExplorationStateChangeListener { enabled ->
+            isTouchExplorationEnabled = enabled
+        }
+        accessibilityManager.addTouchExplorationStateChangeListener(listener)
+        onDispose {
+            accessibilityManager.removeTouchExplorationStateChangeListener(listener)
+        }
+    }
+    return isTouchExplorationEnabled
 }