fix(android): replace std::format with std::to_string in graphicsConversions.h for C++17 compatibility

[shubhamd99]

Summary

This patch fixes a build failure on Android in React Native 0.83 caused by the use of std::format in
react/renderer/core/graphicsConversions.h. Android builds use C++17 and the Android NDK does not support
std::format (a C++20 feature), which leads to compile/link errors (e.g., undefined symbol and missing
std::format on Windows and other environments).

The problematic line has been replaced with a C++17-compatible implementation using std::to_string + "%".

Motivation

• std::format is not available in the Android NDK’s C++17 toolchain.
• This issue causes native build errors on Windows, Linux, and macOS when building React Native apps on
  0.83 and potentially other versions that include this code.
• The original code breaks Fabric/Codegen builds due to missing symbols and unsupported language features.

This commit resolves the issue by using a supported alternative that produces the same result.

Changes

• File: ReactCommon/react/renderer/core/graphicsConversions.h

• Before:

  case YGUnitPercent:
    return std::format("{}%", dimension.value);
  
  

Summary:

Changelog:

Test Plan:

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[cipolleschi]

I don't think this is the right fix. React Native should build with C++20.
iOS already builds with C++20 and Hermes is building with C++20 too. I'm surprised to learn that Android is building with C++17, tbh.
@cortinico is this a regression?

[cortinico]

I don't think this is the right fix. React Native should build with C++20.
iOS already builds with C++20 and Hermes is building with C++20 too. I'm surprised to learn that Android is building with C++17, tbh.

We do already build with C++20 on Android:

react-native/packages/react-native/ReactCommon/cmake-utils/react-native-flags.cmake

Line 17 in 0cda10b

-std=c++20

so I'm unsure what this fix is about @shubhamd99
Are you trying to build React Native using C++17?

[shubhamd99]

React Native should build with C++20.

not able to build with std::format in android in windows 11, its throwing error during gradlew run

[cortinico]

not able to build with std::format in android in windows 11, its throwing error during gradlew run

Closing as this is not fixing your problem. Currently we don't support building React Native from source on Windows