Wait for the app to come back before asking Compose about it

The save test failed an API 35 leg with "No compose hierarchies found in
the app". Dismissing the POST_NOTIFICATIONS dialog presses back and waits
for the permission UI to be gone, but going away and the app being in front
again are not the same moment, and the next Compose query landed in the gap.

Asked of UiAutomator rather than through awaitAppFocus, which is the
opposite of what this class argues for elsewhere and is right here:
awaitAppFocus goes through composeRule.waitUntil, so it would raise the very
error it is being used to avoid.

Two more local API 34 runs at 70/0/0/3.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

app/src/androidTest/java/org/libremediaconverter/saf/SafPickerRoundTripTest.kt

@@ -595,10 +595,20 @@ class SafPickerRoundTripTest {
      * all and the conversion is already under way.
      */
     private fun dismissThePermissionDialog() {
-        if (device.wait(Until.hasObject(By.pkg(PERMISSION_UI_PACKAGE)), PERMISSION_DIALOG_MS) == true) {
-            device.pressBack()
-            device.wait(Until.gone(By.pkg(PERMISSION_UI_PACKAGE)), PERMISSION_DIALOG_MS)
+        if (device.wait(Until.hasObject(By.pkg(PERMISSION_UI_PACKAGE)), PERMISSION_DIALOG_MS) != true) {
+            return
         }
+        device.pressBack()
+        device.wait(Until.gone(By.pkg(PERMISSION_UI_PACKAGE)), PERMISSION_DIALOG_MS)
+        // And wait for the app to be in front again before anything asks Compose about it.
+        // Querying while another window still owns the screen raises "No compose hierarchies found
+        // in the app", which is what this test did on an API 35 leg: the back press had landed but
+        // the dialog had not finished going away.
+        //
+        // Asked of UiAutomator rather than through awaitAppFocus, which is the opposite of what the
+        // class KDoc argues for elsewhere and is right here: awaitAppFocus goes through
+        // composeRule.waitUntil, so it would raise the very error it is being used to avoid.
+        device.wait(Until.hasObject(By.pkg(context.packageName)), FOCUS_TIMEOUT_MS)
     }
 
     /**