writePlatformInfo function
Stores the Flutter target platform string and emulator flag for the active
session. Written by fdb launch, read by fdb screenshot.
Format: <targetPlatform> <emulator> e.g. ios true or android-arm64 false.
Implementation
void writePlatformInfo(String targetPlatform, bool emulator) {
File(platformFile).writeAsStringSync('$targetPlatform $emulator');
}