binary-expression-operand-order: Allow both sides to be literals

[andy-hanson]

PR checklist

• Addresses an existing issue: binary-expression-operand-order wrong for all-numeric expressions #2866
• New feature, bugfix, or enhancement
  • Includes tests
• Documentation update

Overview of change:

Allow 1 + 1.

CHANGELOG.md entry:

[bugfix] binary-expression-operand-order: Allow if both sides of the binary expression are literals.

[ChrisMBarr]

Related and probably already covered by the merged in fix, but I ran into this issue with the following line of code

public static dayInMilliseconds = 24 * 60 * 60 * 1000;