fix(scanner-effect): lower default DPI in ScannerEffectRequest (#4565)

# Description of Changes

On High preset the Scanner-effect request was blocked on default since
max DPI is 500. This meant if users **tried** to use Scannereffect on
default DPI limit, and default ScannerEffect setting then they would get
error. This update lowers default high preset's DPI to 300 so that is
under the default limit.

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## Checklist

### General

- [x] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [x] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [x] I have performed a self-review of my own code
- [x] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [x] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

Signed-off-by: Balázs Szücs <bszucs1209@gmail.com>

app/core/src/main/java/stirling/software/SPDF/model/api/misc/ScannerEffectRequest.java

@@ -101,7 +101,7 @@ public class ScannerEffectRequest {
         this.noise = 1.0f;
         this.brightness = 1.02f;
         this.contrast = 1.05f;
-        this.resolution = 600;
+        this.resolution = 300;
     }
 
     public void applyMediumQualityPreset() {