fix(e2e): Make Android crash flag auto-expire after one crash

The crash flag file was persisting across app launches, causing the app
to crash indefinitely. Now the flag auto-deletes when read, allowing:
1. First launch: Enable flag
2. Second launch: Read flag, delete it, then crash
3. Third launch: Start normally and send crash report

This solves the chicken-and-egg problem where the app couldn't reach
JavaScript to clear the flag because it kept crashing before JS loaded.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: antonis

samples/react-native/android/app/src/main/java/io/sentry/reactnative/sample/MainApplication.kt

@@ -56,6 +56,12 @@ class MainApplication :
     private fun shouldCrashOnStart(): Boolean {
         // Check if crash flag file exists (for E2E testing)
         val crashFile = getFileStreamPath(".sentry_crash_on_start")
-        return crashFile.exists()
+        if (crashFile.exists()) {
+            // Delete the flag immediately so we only crash once
+            // This allows the next launch to succeed and send the crash report
+            crashFile.delete()
+            return true
+        }
+        return false
     }
 }

samples/react-native/e2e/tests/captureAppStartCrash/captureAppStartCrash.test.android.manual.yml

@@ -18,29 +18,13 @@ appId: io.sentry.reactnative.sample
 - tapOn: "Enable Crash on Start"
 - stopApp
 
-# Second launch: App will crash on start due to flag file
+# Second launch: App crashes on start
+# The crash flag auto-deletes when read, so app only crashes once
 - launchApp:
     clearState: false
     stopApp: false
 
-# Third launch: Crash event is sent before crashing again
+# Third launch: App starts normally and sends the crash event
 - launchApp:
     clearState: false
     stopApp: false
-
-# Fourth launch: Disable the crash flag so app can run normally
-- launchApp:
-    clearState: false
-    stopApp: false
-
-# Wait for app to stabilize
-- waitForAnimationToEnd:
-    timeout: 2000
-
-# Scroll down to find the "Disable Crash on Start" button
-- scrollUntilVisible:
-    element: "Disable Crash on Start"
-    timeout: 10000
-    direction: DOWN
-
-- tapOn: "Disable Crash on Start"