AddOrUpdateAnnotationAttribute respects appendArray with string literals

[steve-aom-elliott]

Summary

• When appendArray=true and the existing annotation value is a string literal (not already an array), the recipe now converts it to an array and appends the new values
• Added helper method createNewArrayWithExistingAndNew() to handle the conversion
• Added test for implicit value attribute case

Problem

AddOrUpdateAnnotationAttribute did not respect the appendArray option when the existing annotation value was a string literal rather than an array. It would replace the value instead of appending.

Example:

• Input: @Foo(bars = "abc") with appendArray=true and attributeValue="xyz"
• Expected: @Foo(bars = {"abc", "xyz"})
• Actual: @Foo(bars = "xyz")

Solution

Added checks in update(J.Assignment ...) and update(J.Literal ...) methods to detect when appendArray=true and the attribute is an array type but the current value is a literal. In these cases, we now convert the literal to an array containing both the existing value and the new values.

Test plan

• Existing tests pass
• New test respectsAppendArrayWhenGoingFromImplicitLiteralValueToArray() added
• Existing tests respectsAppendArrayWhenGoingFromLiteralToArraySingle and respectsAppendArrayWhenGoingFromLiteralToArrayMulti now pass