Errors parsing JSON_VALUE

[kylechadha]

Describe the Bug
error: :3: got "(" while expecting ")" while parsing JSON_VALUE. This is an issue with the underlying Spanner parsing lib, which has been fixed in googleapis/google-cloud-go#5173

Steps to Reproduce
Attempt to run a migration with the following DDL:

ALTER TABLE products ADD COLUMN item STRING(MAX) AS (JSON_VALUE(itemDetails, '$.itemDetails')) STORED;

Expected Behavior
No errors.

Migrate Version
v4.5.1

Loaded Source Drivers
e.g. s3, github, go-bindata, gcs, file
Obtained by running: migrate -help

Loaded Database Drivers
github, github-ee, go-bindata, gcs, s3, bitbucket, gitlab, godoc-vfs, file

Go Version
go version go1.16.3 darwin/amd64

Stacktrace
N/A

Additional context
PR to fix: #669

[kylechadha]

Linking PR: #669