Log unrecognized font family on Android

[mosab-nasrallah]

Summary:

On Android, a fontFamily that can't be resolved silently falls back to the default system font. iOS logs Unrecognized font family '<name>' in the same case (RCTFont.mm). This adds the same log on Android, only when Typeface.create falls back to the default typeface, so valid system families like monospace don't log. Like RCTLogInfo on iOS, it only runs in debug builds.

Fixes #58750

Replaces #58751, which was closed by accident when its fork got detached.

Changelog:

[ANDROID] [ADDED] - Log unrecognized font families, matching iOS

Test Plan:

Ran this branch's ReactFontManager.kt in a test app on an API 35 emulator and checked logcat. Debug build:

• 'FontFamilyThatDoesNotExist' logs Unrecognized font family 'FontFamilyThatDoesNotExist' (once per style)
• 'monospace', 'serif', 'sans-serif', 'sans-serif-medium', 'cursive', fonts in assets/fonts/ and fonts added with addCustomFont log nothing
• Every font family name declared on the device (34 names, all 4 styles) logs nothing

Release build: nothing is logged, including for 'FontFamilyThatDoesNotExist'.

Repro: RNTesterPlayground.js

[mosab-nasrallah]

@javache I moved this to a new PR because #58751 was closed by accident. This addresses both of your comments:

• Accuracy: it now only logs when Typeface.create falls back to the default typeface (Typeface.defaultFromStyle(style)), and it skips sans-serif, since that is the default family. It also uses the same message as iOS. I checked every system font family name on an API 35 emulator, and none of them trigger the log.
• Cost: the existing code already called Typeface.create(fontFamilyName, style) and returned it. This keeps that call, so it doesn't create an extra Typeface. Typeface.defaultFromStyle(style) returns one of the 4 default instances Android creates at startup, and this path only runs once per font family and style because of fontCache. I measured the check at about 25–30 ns on an API 35 emulator (release build), compared to about 57 µs for the two failed asset lookups that already run here. It's also now wrapped in ReactBuildConfig.DEBUG, so release builds skip it entirely, which matches RCTLogInfo on iOS.

[meta-codesync]

@fabriziocucci has imported this pull request. If you are a Meta employee, you can view this in D122984557.

[cortinico]

Review automatically exported from Phabricator review in Meta.

[meta-codesync]

@fabriziocucci merged this pull request in c1401a1.