Add Detox end-to-end tests for core payment flows

[manideepk90]

Create comprehensive Detox test cases for Android payment flows:

Test Cases to Implement:

1. Payment Normal Flow

   • Successful card payment completion
   • Form validation and submission
   • Success screen verification

2. Payment Cancelled Flow

   • User cancels payment mid-flow
   • Back button handling
   • Proper cleanup and state reset

3. Payment Failed Flow

   • Invalid card details handling
   • Network failure scenarios
   • Error message display and retry options

Expected Outcome:

• 3 new test files in detox-tests/
• Tests should run on Android emulator
• Proper assertions for each flow state

Files to Create:

• detox-tests/e2e/android/paymentFlow.test.js
• detox-tests/e2e/android/paymentCancel.test.js
• detox-tests/e2e/android/paymentFailure.test.js

Acceptance Criteria:

• All tests pass on Android emulator
• Tests use proper Detox matchers and actions
• Error scenarios are properly handled
• Tests are documented with clear descriptions