fix(patch): cherry-pick edbe548 to release/v0.21.0-preview.4-pr-15007 to patch version v0.21.0-preview.4 and create version 0.21.0-preview.5 (#15015)

Co-authored-by: Abhi <43648792+abhipatel12@users.noreply.github.com>

Author: gemini-cli-robot

packages/core/src/policy/policies/read-only.toml

@@ -56,6 +56,6 @@ decision = "allow"
 priority = 50
 
 [[rule]]
-toolName = "codebase_investigator"
+toolName = "SubagentInvocation"
 decision = "allow"
 priority = 50