Change default value of setElegantTextFlag

As a first step of deprecating UI fonts, make setElegantTextFlag as true
by default if the target SDK is set to Android 15 or later..

Bug: 279646685
Test: atest PaintDefaultsTest
Change-Id: If8e40c075122cafd2f89ae703bf6a5f07ebc7bd0
6 files changed