Add if-cap-support for If-OTU4-ODU4 ports (7.1)

Add if-cap-support for If-OTU4-ODU4 ports (7.1)

- Currently the if-capability support is missing for IfOTU4ODU4
  type ports for 7.1 devices.
- Port-mapping fails to mount the NE with a null pointer expection when
  the supporting-interface-capabilities are not present in MappingUtilImpl.
- Add code to avoid null-pointer expection, even when the MappingUtilImpl
  does not contain required supported-if-cap.

JIRA: TRNSPRTPCE-747

Change-Id: I0270f99a93a02107a7c9a66f49e9825c65b06242
Signed-off-by: Balagangadhar (Bala) Bathula <bb4341@att.com>