[Android] Video filter still active after closing content

Description

On Android, any video filter chosen after loading content is still active after closing content. On windows this does not happen.

Expected behavior

Video filters should work the same as any setting. If you select one (like any of the Blaarg filters) after loading content, the specific filter should only be remembered by the core, if overrides are saved for that core, and the setting should be back to the state it was before loading content.

Example: If no filter was selected when opening retroarch, and then loading content and selecting a filter, no filter should be active after closing content. Only remembered by the core if core/game overrides were saved.

Actual behavior

After loading content with no video filter previously loaded, and choosing any video filter in video settings. When closing content, the video filter is still active, instead of rolling back to the default state of no video filter selected.

The filter is even active when loading different content in other cores with no previously filter related override saved.

Steps to reproduce the bug

1. Open Retroarch with default setting (no video filter active).
2. Load content.
3. With said content still loaded, pick a video filter in video settings (optionally saving core overrides)
4. Close content.
5. Video filter is still selected.
6. Load different content.
7. Same video filter still selected.

Retroarch version: Latest stable 1.96
Systems: [Android]
Mipad 4, MIUI 10.3.2
Android 8.1.0
3 GB ram, Octa-core max 2.20 GHz, Armv8

Start by reproducing the issue on Android using the listed steps, then trace how video-filter settings change after content is loaded and closed. Done means a filter selected during content playback is cleared when no override applies, while saved core or game overrides remain effective for the relevant content.