Fix: state loss in SearchActivity and MediaDetailPagerFragment during screen rotation

[Kota-Jagadeesh]

Description (required)

What changes did you make and why?

1. Implemented State Restoration in SearchActivity: added tha onSaveInstanceState to track the current media position and updated onCreate to restore the media detail view if a position was previously saved. This replaces the previous temporary fix in onResume which forced a back-press on rotation.
2. Synchronized MediaDetailPagerFragment: Updated the fragment to save and restore its internal ViewPager current item index.
3. Improved UX & Navigation: By using binding.root.post for restoration, I ensured the UI is fully laid out before re-opening details, preventing crashes and ensuring the user stays on the same image they were viewing before rotating the device.
4. Cleaned up Fragment Stack: Removed the onBackPressed() call from onResume() which was an anti-pattern causing the fragment back-stack to increase incorrectly.

Tests performed (required)

Tested ProdDebug on Redmi Note 13 Pro with API level 35.

• Verified that rotating from Portrait to Landscape while viewing an image detail does not return the user to the search results list.
• Verified that the Back button correctly returns the user to the search results after a rotation occurs.
• Verified that isFeaturedImage and editable flags are preserved after rotation, keeping menu items consistent.

[github-actions]

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