optimize: simplify and groom configuration items

[slievrly]

Signed-off-by: slievrly slievrly@163.com

Ⅰ. Describe what this PR did

optimize: simplify and groom configuration items

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 #1838 into develop will increase coverage by <.01%.
The diff coverage is 11.53%.

@@             Coverage Diff              @@
##             develop   #1838      +/-   ##
============================================
+ Coverage      55.39%   55.4%   +<.01%     
+ Complexity      2378    2376       -2     
============================================
  Files            422     422              
  Lines          14314   14319       +5     
  Branches        1716    1716              
============================================
+ Hits            7929    7933       +4     
+ Misses          5652    5645       -7     
- Partials         733     741       +8

Impacted Files	Coverage Δ	Complexity Δ
...ava/io/seata/core/constants/ConfigurationKeys.java	0% <ø> (ø)	0 <0> (ø)	⬇️
...ata/core/store/db/AbstractDataSourceGenerator.java	0% <0%> (ø)	0 <0> (ø)	⬇️
...o/seata/server/coordinator/DefaultCoordinator.java	48.01% <14.63%> (-1.59%)	27 <2> (-1)
...server/store/file/FileTransactionStoreManager.java	59.21% <0%> (-0.99%)	29% <0%> (ø)
...in/java/io/seata/server/session/GlobalSession.java	84.54% <0%> (-0.49%)	67% <0%> (-1%)
.../java/io/seata/core/rpc/netty/NettyBaseConfig.java	36.11% <0%> (+13.88%)	2% <0%> (ø)	⬇️

[xingfudeshi]

LGTM.

[zjinlei]

LGTM