fix(functions): make swift/objective-c interop work in non-use_frameworks! case

the new pre-built react-native core for iOS is not built with use_frameworks, so
header imports that assume a module is in a framework (that is, angle-bracket imports)
do not resolve

in that case we can fall back on a direct header path import, which works via cocoapods
adding the build header path where the Swift interop file goes to the build search path

Author: mikehardy

packages/functions/ios/RNFBFunctions/RNFBFunctionsModule.mm

@@ -18,13 +18,24 @@
 #import <Firebase/Firebase.h>
 #import <React/RCTUtils.h>
 
-#import <RNFBFunctions/RNFBFunctions-Swift.h>
 #import "NativeRNFBTurboFunctions.h"
 #import "RNFBApp/RCTConvert+FIRApp.h"
 #import "RNFBApp/RNFBRCTEventEmitter.h"
 #import "RNFBApp/RNFBSharedUtils.h"
 #import "RNFBFunctionsModule.h"
 
+#if __has_include(<RNFBFunctions/RNFBFunctions-Swift.h>)
+// This import will work in situations where `use_frameworks!` is in use
+#import <RNFBFunctions/RNFBFunctions-Swift.h>
+#elif __has_include("RNFBFunctions-Swift.h")
+// If `use_frameworks!` is not in use (for example, while using pre-built
+// react-native core) then header imports based on frameworks assumptions fail.
+// So, if frameworks are not available, fall back to importing the header directly, it
+// should be findable from a header search path pointing to the build
+// directory. See firebase-ios-sdk#12611 for more context.
+#import "RNFBFunctions-Swift.h"
+#endif
+
 static __strong NSMutableDictionary *streamListeners;
 
 @implementation RNFBFunctionsModule