fix: truncate app name to avoid import spfx failure

[HuihuiWu-Microsoft]

ADO: https://msazure.visualstudio.com/Microsoft%20Teams%20Extensibility/_workitems/edit/25578888

[codecov]

Codecov Report

Merging #10210 (f992934) into dev (041c93f) will decrease coverage by 0.01%.
Report is 4 commits behind head on dev.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##              dev   #10210      +/-   ##
==========================================
- Coverage   91.94%   91.93%   -0.01%     
==========================================
  Files         453      453              
  Lines       26278    26269       -9     
  Branches     5055     5057       +2     
==========================================
- Hits        24160    24151       -9     
  Misses       1876     1876              
  Partials      242      242              

Files	Coverage Δ
...core/src/component/generator/spfx/spfxGenerator.ts	93.06% <100.00%> (+0.10%)	⬆️
...re/src/component/generator/spfx/utils/constants.ts	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes