Add Sinhala (Sri Lanka) Locale Support

[kumuditha-udayanga]

Fixes #2033

Changes:
Add Sinhala translation to string.xml.

Screenshot/s for the changes: [Add screenshot/s of the layout where you made changes or a *.gif containing a demonstration]

Checklist: [Please tick following check boxes with [x] if the respective task is completed]

• I have used resources from strings.xml, dimens.xml and colors.xml without hard-coding them
• No modifications done at the end of resource files strings.xml, dimens.xml or colors.xml
• I have reformatted code in every file included in this PR [CTRL+ALT+L]
• My code does not contain any extra lines or extra spaces
• I have requested reviews from other members

APK for testing: [Compress the app-debug.apk file into a <feature>.rar or <feature>.zip file and upload it here]

app-fdroid-debug.apk.zip

[jayasanka-sack]

You have done a great job with the translation @kumuditha-udayanga !
BTW, there are some words required to change. I've marked them with this review.

PS: I'm a native Sinhalese speaker.

[jayasanka-sack]

Add these too..

[jayasanka-sack]

@kumuditha-udayanga
Fix these changes too... (Hopefully last change request 😁)

[kumuditha-udayanga]

All Changes have been done @jayasanka-sack @Piumal1999 could you please review it

[jayasanka-sack]

Perfect!

[kumuditha-udayanga]

@mariobehling @CloudyPadmal @cweitat It would be nice to have your reviews on this.

[harshamc00]

Sinhala Translations will indeed be a value-adding feature to the application. As a native Sinhala speaker, I can verify that translations a correct.

[CloudyPadmal]

Nice. Let this PR be an example of how language translation PRs should be evaluated.