#### Why I did it
Some tests under platform_tests/api were failing on the 7050CX3 due to outdated facts in platform.json
#### How I did it
Updated platform.json facts with appropriate values
#### How to verify it
Run tests under platform_tests/api to verify no failures
platform.json is needed for sonic-mgmt testing. Also in the future it will be used as part of dynamic port breakout.
Also removed the folder symlink for BlackhawkDD because it has a different platform.json than BlackhawkO.
Co-authored-by: Zhi Yuan Carl Zhao <zyzhao@arista.com>