Sonar blocker issue resolution
Sonar issue resolutions for RestClientInvoker.java
Resolve Blocker issue:
https://sonar.onap.org/issues/search#issues=AWBzdRXQ-08if2a6vsl1
And other sonar findings:
https://sonar.onap.org/issues/search#issues=AWBzdRXP-08if2a6vslw
https://sonar.onap.org/issues/search#issues=AWBzdRXP-08if2a6vslx
https://sonar.onap.org/issues/search#issues=AWBzdRXP-08if2a6vsly
https://sonar.onap.org/issues/search#issues=AWBzdRXQ-08if2a6vslz
https://sonar.onap.org/issues/search#issues=AWBzdRXQ-08if2a6vsl0
https://sonar.onap.org/issues/search#issues=AWBzdRXP-08if2a6vslv
https://sonar.onap.org/issues/search#issues=AWBzdRXQ-08if2a6vsl2
Change-Id: Ic9d834f223db49bf0c02e51f334b3f93ace263cd
Issue-ID: APPC-387
Signed-off-by: Skip Wonnell <skip@att.com>