Hello Nikhil,
You are using the 6.0 version of the CFamily analyzer, that no longer allows you to bypass the build wrapper (it was creating too many issues). So if you want to analyze C, C++ or objective-C code, you have to setup your environment so that you run the build wrapper and then use its output.
If you are only interested in Swift code, the way to go is to exclude source code from the other languages, as you already started to do. You are listing some extensions used by the CFamily analyzer, but not .h (headers) or .m (objective-C). Another option would be to use sonar.inclusions instead of sonar.exclusions to list only the extensions associated with Swift.
There is another option, that might be easier to use if you need inclusions/exclusions for another purpose: Each language has a list of file suffixes it uses to recognize its source files. So you could set those suffixes to values that do not appear in your codebase:
sonar.c.file.suffixes=disable_this_analysis
sonar.cpp.file.suffixes=disable_this_analysis_too
sonar.objc.file.suffixes=and_disable_this_to_totally_disable_cfamily