Static code analysis: potential lock collisions FileProcessId#getpid - interned string used as a lock

CID-17581: Bad choice of lock object - Potential lock collisions

at class `FileProcessId`[6] method `getpid` with error message

Interned string as a lock may cause deadlocks or performance problems if a library also uses the interned string as a lock.
 string_literal: The string literal "0x" is an interned string.
 interned_string_lock: Locking on an interned string can cause unexpected locking collisions with third party code.
 Instead of using "0x" as a lock, create a final field of type Object which is only used as a lock.

See Java examples at Coverity page [7]. The explanation there is that
  String literals are centrally interned and could also be locked on by a
library, causing you to potentially have deadlocks or lock collisions
with other code.
There are several places [8] on net when searching for `java synchronzation on strings`.

[6] https://github.com/jbosstm/narayana/blob/master/ArjunaCore/arjuna/classes/com/arjuna/ats/internal/arjuna/utils/FileProcessId.java#L63
[7] https://ondemand.coverity.com/reference/7.6.1/en/coverity#N5069A
[8] http://www.javalobby.org/java/forums/t96352.html