Don't use masked appearance in text number widget

[seadowg]

Closes #6214

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

Not a lot to discuss as this just updates how we determine whether to use masked or not.

I've also removed tests around not using the masked appearance in the tests for subclasses of StringWidget and ExStringWidget as this is handled in the respective parent class tests. This was a follow-up to #6187.

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?

Main changes are just around how masked applied.

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

[dbemke]

Tested with Success!

Verified on devices with Android 10,14

Verified Cases:

• issue Answer entered in masked text numbers question can be seen on android keyboard in landscape view #6214 doesn't occur
• forms with masked widgets
• rotating the screen