isExpression and getExpression doesn't work on newly created properties

[mkrussel77]

I'm trying to unit test the calls to setProperties and the interrogation of the state of the expression is invalid.

Steps to reproduce

PropertyValue<?> property = lineWidth(Expression.get("width"))
assertTrue(property.isExpression())
assertEquals(Expression.get("width"), property.getExpression())

Expected behavior

Both assertions pass

Actual behavior

Neither pass

Android versions: N/A
Device models: N/A
Mapbox SDK versions: 6.4.0