Improve help strings for radware LbaaS driver

Make strings consistent with what we use elsewhere:
* Capitalize first word
* End with "."
* Improve wording and spelling

Partial-Bug: #1315111
Change-Id: Ic378aa7e4f936c3f3da0a23598620c3b978cbf45
Merge "Improve help strings for radware LbaaS driver"