Proposed Changes

Use best-matched font rather than "hardcoded"

The original part

final FontStyle defaultStyle = new FontStyle(
        (style & Typeface.BOLD) != 0 ? FontStyle.FONT_WEIGHT_BOLD
                : FontStyle.FONT_WEIGHT_NORMAL,
        (style & Typeface.ITALIC) != 0 ? FontStyle.FONT_SLANT_ITALIC
                : FontStyle.FONT_SLANT_UPRIGHT
);
return new Typeface.CustomFallbackBuilder(familyBuilder.build())
       .setStyle(defaultStyle)
       .build();

This will make the final Typeface ALWAYS have either 400 (FONT_WEIGHT_NORMAL) or 700 (FONT_WEIGHT_BOLD) weight. It is incorrect since fonts passed to these methods could have other font-weight. For example, pass only one font with 500 weight, the final Typeface will have 400 weight, making the fallback font displayed as 400 weight rather than 500.

This pull request copies the platform's algorithm to find the best-match font from the font family.

Testing

Test: Observed that the font weight is correct

Issues Fixed

Fixes: Fix https://issuetracker.google.com/issues/194553426