In mysql source, all the plugins might not be in the same location. Some mtr
tests would require multiple plugins, so it is desirable that there is a
check to see that, if all the plugins are in a directory, then the test
should run, else it needs to be skipped.

Steps involved in this inc file :
1. Take a plugins list.
2. check if all plugins are in same directory.
3. If yes, continue with the test.
4. If no, Skip the test.