Feature Request: AutoMigrate supports placement of geo-partitioning

[gsbingo17]

Now the AutoMigrate does not support the placement in Create Table SQL statement.

Please refer to the following SQL statement

CREATE TABLE Companies (
  id INT64 NOT NULL, 
  create_at timestamp, 
  update_at timestamp,
  name STRING(MAX) NOT NULL, 
  Location STRING(MAX) NOT NULL PLACEMENT KEY
)  PRIMARY KEY(id)

Please add the support to placement key in the AutoMigrate tool.