Fixed displaying the number of unsupported layers

[grzesiek2010]

Closes #6237

Why is this the best possible solution? Were any other approaches considered?

It's just a small bug fix. Nothing to discuss here.

How does this change affect users? Describe intentional changes to behavior and behavior that could have accidentally been affected by code changes. In other words, what are the regression risks?

It should just fix the number of unsupported layers displayed in the warning dialog.

Do we need any specific form for testing your changes? If so, please attach one.

No.

Does this change require updates to documentation? If so, please file an issue here and include the link below.

No.

Before submitting this PR, please make sure you have:

• added or modified tests for any new or changed behavior
• run ./gradlew connectedAndroidTest (or ./gradlew testLab) and confirmed all checks still pass
• added a comment above any new strings describing it for translators
• added any new strings with date formatting to DateFormatsTest
• verified that any code or assets from external sources are properly credited in comments and/or in the about file.
• verified that any new UI elements use theme colors. UI Components Style guidelines

[srujner]

Tested with Success!

Verified on device with Android 13

Verified cases:

• Issue Wrongly showing the number of layers that can't be added #6237 is no longer reproducing;
• Check on the rest of the offline layers functionality;
• Adding Big layers/multiple layers at once;
• Adding layers to current/all projects;
• Don't keep activities enabled/disabled

[dbemke]

Tested with Success!

Verified on device with Android 10