Implicit API: local PropagateTags: false is silently overridden by global PropagateTags: true

Describe the bug

ImplicitApiPlugin._add_tags_to_implicit_api_if_necessary() decides whether to copy a resource's Tags onto its generated implicit AWS::Serverless::Api/HttpApi resource using:

should_propagate_tags = resource.properties.get("PropagateTags") or globals_var.get("PropagateTags")

PropagateTags is documented as bool | None (see samtranslator/internal/schema_source/aws_serverless_function.py), where None means "not set" and False is a meaningful, explicit opt-out. Using or means a local PropagateTags: false is indistinguishable from "not set" — it silently falls through to the global value.

Reproduction

Globals:
  Function:
    PropagateTags: true
    Tags:
      Team: Data

Resources:
  MyFunction:
    Type: AWS::Serverless::Function
    Properties:
      PropagateTags: false        # explicit opt-out
      Runtime: python3.12
      Handler: index.handler
      CodeUri: s3://bucket/key
      Events:
        Api:
          Type: Api
          Properties:
            Path: /hello
            Method: get

Expected behavior

The function explicitly disables PropagateTags, so the generated implicit AWS::Serverless::Api should NOT receive the Team: Data tag.

Actual behavior

resource.properties.get("PropagateTags") returns False (falsy), so or evaluates the global value (True) instead, and the tag is propagated to the implicit API anyway — silently ignoring the resource-level override.

This is inconsistent with the standard Globals merge logic (GlobalProperties._prefer_local in samtranslator/plugins/globals/globals.py), which always prefers the local value when the key is present locally, regardless of its truthiness.

Fix

PR incoming.