fix: properly handle thread interrupts during gRPC channel shutdown

[KaviarasuSakthivadivel]

When InterruptedException is caught during channel.awaitTermination(),
the thread's interrupt status is cleared. This fix restores the interrupt
status following Java best practices to ensure proper interrupt propagation.

Changes:

• Restore interrupt status with Thread.currentThread().interrupt()
• Improve logging to distinguish timeout from interrupt

This ensures thread pools and upstream callers can properly detect
that the thread was interrupted.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.79%. Comparing base (97bc515) to head (26fd1ac).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #159      +/-   ##
============================================
+ Coverage     82.73%   82.79%   +0.06%     
  Complexity     1347     1347              
============================================
  Files           111      111              
  Lines          4055     4058       +3     
  Branches        413      413              
============================================
+ Hits           3355     3360       +5     
+ Misses          510      508       -2     
  Partials        190      190              

Components	Coverage Δ
JDBC Core	83.98% <100.00%> (+0.07%)	⬆️
JDBC Main	40.69% <ø> (ø)
JDBC HTTP	91.09% <ø> (ø)
JDBC Utilities	66.07% <ø> (ø)
Spark Datasource	∅ <ø> (∅)

Files with missing lines	Coverage Δ
...ce/datacloud/jdbc/core/JdbcDriverStubProvider.java	94.11% <100.00%> (+15.54%)	⬆️

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