fix(sysadvisor): fix isolacted size calculated incorrectly

[cheney-lin]

What type of PR is this?

Bug fixes

What this PR does / why we need it:

Which issue(s) this PR fixes:

Special notes for your reviewer:

[codecov]

Codecov Report

Attention: Patch coverage is 80.00000% with 4 lines in your changes missing coverage. Please review.

Project coverage is 56.89%. Comparing base (29d4745) to head (0807cf1).
Report is 5 commits behind head on main.

Files	Patch %	Lines
...u/assembler/provisionassembler/assembler_common.go	80.00%	2 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #656      +/-   ##
==========================================
- Coverage   57.00%   56.89%   -0.11%     
==========================================
  Files         552      553       +1     
  Lines       52838    53177     +339     
==========================================
+ Hits        30118    30257     +139     
- Misses      18941    19127     +186     
- Partials     3779     3793      +14     

Flag	Coverage Δ
unittest	56.89% <80.00%> (-0.11%)	⬇️

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