Fix text color contrast issue on Caption size and style screen

Use the same textAppearance as the one defined in
preset_picker_item.xml, which is used by the Edge type dialog on the
same screen and doesn't have text color contrast issue.

Bug: 319742556
Flag: EXEMPT (simple bug fix)
Test: Manually by using Accessibility Scanner

Change-Id: If078ce1daf8ba0b3cb6ffef860ff39e995d7446a