Update type of *LogRotate variables to volatile sig_atomic_t

[bocon13]

Currently the LogRotate variables in orchagent/main.cpp are not signal safe.

https://en.cppreference.com/w/cpp/utility/program/signal

bool should be changed to volatile sig_atomic_t or atomic_bool:
https://github.com/Azure/sonic-swss/blob/bb0733aa67ffc4e430e70bcf2db2dc6316172b32/orchagent/main.cpp#L57-L58

Then, references are safe in the signal handler:
https://github.com/Azure/sonic-swss/blob/bb0733aa67ffc4e430e70bcf2db2dc6316172b32/orchagent/main.cpp#L95-L102

References to these variables should happen atomically in the log rotation code. For example,
https://github.com/Azure/sonic-swss/blob/ceca17c9b83db4dc1df517026e2153c730b4cf9f/orchagent/response_publisher.cpp#L40-L44

Should use atomic exchange.

 if (!gResponsePublisherLogRotate.exchange(false)) 
 { 
     return; 
 }