create-for-rbac: ensure SP's end date will not exceed certificate's expiration date

[yugangw-msft]

Fix #2989

General Guidelines

• The PR has modified HISTORY.rst with an appropriate description of the change (see Modifying change log).

Command Guidelines

• Each command and parameter has a meaningful description.
• Each new command has a test.

(see Authoring Command Modules)

[codecov-io]

Codecov Report

Merging #2990 into master will increase coverage by <.01%.
The diff coverage is 55.88%.

@@            Coverage Diff             @@
##           master    #2990      +/-   ##
==========================================
+ Coverage   63.36%   63.37%   +<.01%     
==========================================
  Files         463      463              
  Lines       26599    26621      +22     
  Branches     4087     4092       +5     
==========================================
+ Hits        16854    16870      +16     
- Misses       8628     8633       +5     
- Partials     1117     1118       +1

Impacted Files	Coverage Δ
...cli-role/azure/cli/command_modules/role/_params.py	100% <100%> (ø)	⬆️
...-cli-role/azure/cli/command_modules/role/custom.py	35.01% <53.12%> (+1.9%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 8bf3245...766b170. Read the comment docs.

[tjprescott]

LGTM. cc/ @devigned