change disk physicaltype

[tanjiangyu-ghca]

What this PR does / why we need it:

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #

Special notes for your reviewer:

Release note:

[codecov]

Codecov Report

Merging #265 (8e3b0bc) into unity_0916 (21180a5) will decrease coverage by 0.04%.
The diff coverage is 100.00%.

@@              Coverage Diff               @@
##           unity_0916     #265      +/-   ##
==============================================
- Coverage       70.34%   70.29%   -0.05%     
==============================================
  Files             163      163              
  Lines           15922    15924       +2     
  Branches         1990     1990              
==============================================
- Hits            11200    11194       -6     
- Misses           4049     4055       +6     
- Partials          673      675       +2     

Impacted Files	Coverage Δ
delfin/drivers/dell_emc/unity/rest_handler.py	48.85% <ø> (ø)
delfin/drivers/dell_emc/unity/unity.py	68.42% <100.00%> (+0.16%)	⬆️
delfin/drivers/fake_storage/__init__.py	93.15% <0.00%> (-2.20%)	⬇️