Apply separate style to question text if type is group.

[santosh-pingle]

IMPORTANT: All PRs must be linked to an issue (except for extremely trivial and straightforward changes).

Fixes #1450

Description
Earlier, it was okay to have single attribute resource to set style to question text in header view in all views, but now requirement is to set different style to question text if type is group. Therefore we can not keep same existing files and set attribute resource at run time in kolin code according to the group type, as there is no such api which which accepts attribute resource.
So created separate xml resource file for group type header view and updated changes accordingly.

Alternative(s) considered
Another approach is to set attribute resource to question text if type is group in header view in kotlin code, but there is no such api which accept attribute as resource to set the style.

Type
Choose one: Feature
Screenshots (if applicable)
Attaching screenshot for demo purpose only.
@shelaghm

Checklist

• I have read and acknowledged the Code of conduct.
• I have read the Contributing page.
• I have signed the Google Individual CLA, or I am covered by my company's Corporate CLA.
• I have discussed my proposed solution with code owners in the linked issue(s) and we have agreed upon the general approach.
• I have run ./gradlew spotlessApply and ./gradlew spotlessCheck to check my code follows the style guide of this project.
• I have run ./gradlew check and ./gradlew connectedCheck to test my changes locally.
• I have built and run the demo app(s) to verify my change fixes the issue and/or does not break the demo app(s).