Fix negative percent issue on Stats for RTL languages

[irfano]

Fixes #17447

When the device language is set to Arabic, numbers with the percentage were being displayed as "%96-". This was the output of android.icu.text.NumberFormat function. I couldn't find any documentation related to this issue, but using java.text.NumberFormat resolves it. See the screenshot below:

before	after

Ignore the inaccurate chart. I manipulated the code to display the negative percentage.

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To Test:

1. Set your device language to Arabic.
2. Open the Jetpack app and head to Stats > Insights, on a site that has less traffic this week than last week.
3. Verify that the negative percentage is displayed correctly.

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Regression Notes

1. Potential unintended areas of impact

   • Other languages.

2. What I did to test those areas of impact (or what existing automated tests I relied on)

   • Tested in Turkish. The percent is displayed as "(-%96)", as expected.

3. What automated tests I added (or what prevented me from doing so)

   • Added PercentFormatterTest.

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PR Submission Checklist:

• I have completed the Regression Notes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

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Testing Checklist (strike-out the not-applying and unnecessary ones):

• WordPress.com sites and self-hosted Jetpack sites.
• Portrait and landscape orientations.
• Light and dark modes.
• Fonts: Larger, smaller and bold text.
• High contrast.
• Talkback.
• Languages with large words or with letters/accents not frequently used in English.
• Right-to-left languages. (Even if translation isn’t complete, formatting should still respect the right-to-left layout)
• Large and small screen sizes. (Tablet and smaller phones)
• Multi-tasking: Split screen and Pop-up view. (Android 10 or higher)

[wpmobilebot]

📲 You can test the changes from this Pull Request in WordPress by scanning the QR code below to install the corresponding build.

	App Name	WordPress
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr20656-8fddc15
	Commit	8fddc15
	Direct Download	wordpress-prototype-build-pr20656-8fddc15.apk

Note: Google Login is not supported on these builds.

[wpmobilebot]

📲 You can test the changes from this Pull Request in Jetpack by scanning the QR code below to install the corresponding build.

	App Name	Jetpack
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr20656-8fddc15
	Commit	8fddc15
	Direct Download	jetpack-prototype-build-pr20656-8fddc15.apk

Note: Google Login is not supported on these builds.

[codecov]

Codecov Report

Attention: Patch coverage is 87.50000% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 40.47%. Comparing base (3f7287b) to head (8fddc15).
Report is 27 commits behind head on trunk.

Files	Patch %	Lines
...rg/wordpress/android/util/text/PercentFormatter.kt	85.71%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            trunk   #20656   +/-   ##
=======================================
  Coverage   40.46%   40.47%           
=======================================
  Files        1485     1485           
  Lines       68443    68450    +7     
  Branches    11312    11312           
=======================================
+ Hits        27696    27704    +8     
+ Misses      38246    38245    -1     
  Partials     2501     2501           

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud

[aditi-bhatia]

Nice work! Works as expected and I tested with a few other languages too