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