optimize: RootContext.java code style

[EZKAYOTWJPRKXWCUYEEB]

Ⅰ. Describe what this PR did

Ⅱ. Does this pull request fix one issue?

Ⅲ. Why don't you add test cases (unit test/integration test)?

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

[codecov-io]

Codecov Report

Merging #2211 into develop will decrease coverage by <.01%.
The diff coverage is 100%.

@@              Coverage Diff              @@
##             develop    #2211      +/-   ##
=============================================
- Coverage      54.34%   54.33%   -0.01%     
- Complexity      2491     2493       +2     
=============================================
  Files            454      454              
  Lines          14871    14864       -7     
  Branches        1749     1749              
=============================================
- Hits            8081     8077       -4     
+ Misses          6019     6018       -1     
+ Partials         771      769       -2

Impacted Files	Coverage Δ	Complexity Δ
...c/main/java/io/seata/compressor/gzip/GzipUtil.java	90% <100%> (+1.11%)	5 <0> (ø)	⬇️
...o/seata/server/coordinator/DefaultCoordinator.java	50.19% <0%> (+0.38%)	31% <0%> (+1%)	⬆️
...in/java/io/seata/server/session/GlobalSession.java	84.61% <0%> (+0.48%)	68% <0%> (+1%)	⬆️

[l81893521]

LGTM

[slievrly]

LGTM