[java] SimplifiedTernary: support for the java.lang.Boolean class

[dykov]

Is your feature request related to a problem? Please describe.
I faced ternary operators with Boolean objects as result:

condition ? Boolean.TRUE : something(); // can be as simple as condition || something()

Describe the solution you'd like
In my opinion, it would be a good solution to disable the use of this class. just like the boolean in the original rule.

[oowekyala]

If something() returns null and you've refactored to condition || something() then your expression NPEs. This is not a problem with a boolean literal (eg condition ? true : (Boolean) null) because that code NPEs too.

I think maybe, UnnecessaryBoxing could carefully* look into whether Boolean.TRUE may be unboxed to true (which here it can't). If it can then SimplifiedTernary would flag it. I don't think this case should be added to SimplifiedTernary.

* boxing rules in ternaries with a primitive type are very complicated...