Reapply "Set FLAG_DECLARATION_FILES value" Have the release config map specify where to find build flag declarations, rather than having the logic in the build system. This reverts commit b737448b4441acc546b333bf251246ab0ffd4bb6. Bug: b/302593603 Test: manual Change-Id: I5e23a5719ad54019dc1e9daa20a1e33fc64af034