Fix bridging header paths for CocoaPods compatibility

Remove Public/ and Private/ path prefixes from import statements
in Branch-Bridging-Header.h. CocoaPods flattens all headers into
a single directory, so relative paths don't work in the built
framework.

Author: wpinho-branch

Sources/BranchSDK/Branch-Bridging-Header.h

@@ -5,10 +5,10 @@
 //  Bridging header to expose Objective-C types to Swift within the Branch target
 //
 
-#import "Public/Branch.h"
-#import "Public/BNCServerRequest.h"
-#import "Public/BNCServerInterface.h"
-#import "Public/BNCServerResponse.h"
-#import "Public/BNCPreferenceHelper.h"
-#import "Public/BranchLogger.h"
-#import "Private/NSError+Branch.h"
+#import "Branch.h"
+#import "BNCServerRequest.h"
+#import "BNCServerInterface.h"
+#import "BNCServerResponse.h"
+#import "BNCPreferenceHelper.h"
+#import "BranchLogger.h"
+#import "NSError+Branch.h"