Add true/false autocomplete suggestions for boolean values in annotations

Currently, autocomplete suggests boolean values for local variables:

and for fields:

but not for annotations:

This is an enhancement request to add these for annotations as well.

Version: 2025-09 (4.37)
Build id: I20250809-1800

The issue names no files or tests; start by tracing the existing boolean autocomplete for local variables and fields, then compare it with annotation completion in the JDT UI. Done means annotation value completion offers true and false in the same way, with tests covering the suggestions.

Written by the indexing model from the issue text.