actions: Improve Action class code for clarity & consistency

actions: Improve Action class code for clarity & consistency

~ Move local variable $obj to one liner as it's redundant in
  this case.
~ Use === check instead of == as in order case above for the
  purpose of consistency.
~ Make use of single quotes for strings literals instead of
  double quotes.

Change-Id: I69650cacb0658a7369147ea5e9933fb5585e3376