Add testcase for setFontVariationOverride

Bug: 361260253
Test: CtsWidgetTestCases
Test: CtsTextTestCases
Test: CtsGraphicsTestCases
Test: minikin_tests
Flag: com.android.text.flags.typeface_redesign_readonly
Change-Id: Ia3b2ddc375a0394576762665d0ca7108b326c9cf
3 files changed