Change filestore network field to a resourceref

[rileykarson]

Fixes hashicorp/terraform-provider-google#11956

If this PR is for Terraform, I acknowledge that I have:

• Searched through the issue tracker for an open issue that this either resolves or contributes to, commented on it to claim it, and written "fixes {url}" or "part of {url}" in this PR description. If there were no relevant open issues, I opened one and commented that I would like to work on it (not necessary for very small changes).
• Generated Terraform, and ran make test and make lint to ensure it passes unit and linter tests.
• Ensured that all new fields I added that can be set by a user appear in at least one example (for generated resources) or third_party test (for handwritten resources or update tests).
• Ran relevant acceptance tests (If the acceptance tests do not yet pass or you are unable to run them, please let your reviewer know).
• Read the Release Notes Guide before writing my release note below.

Release Note Template for Downstream PRs (will be copied)

filestore: fixed a case where `google_filestore_instance.networks.network` would incorrectly see a diff between state and config when the network `id` format was used

[kamal-shaker]

So after this change, I need to change this:

  networks {
    network           = google_compute_network.vpc.id
    modes             = ["MODE_IPV4"]
    connect_mode      = "DIRECT_PEERING"
    reserved_ip_range = "172.16.255.0/29"
  }

To:

  networks {
    network           = google_compute_network.vpc.self_link
    modes             = ["MODE_IPV4"]
    connect_mode      = "DIRECT_PEERING"
    reserved_ip_range = "172.16.255.0/29"
  }

?

[rileykarson]

No- this should add a diff suppress such that your original config works correctly

[modular-magician]

Hi! I'm the modular magician. Your PR generated some diffs in downstreams - here they are.

Diff report:

Terraform GA: Diff ( 1 file changed, 13 insertions(+), 5 deletions(-))
Terraform Beta: Diff ( 1 file changed, 13 insertions(+), 5 deletions(-))
TF Validator: Diff ( 3 files changed, 12 insertions(+), 5 deletions(-))

[modular-magician]

Hi! I'm the modular magician. Your PR generated some diffs in downstreams - here they are.

Diff report:

Terraform GA: Diff ( 1 file changed, 4 insertions(+), 3 deletions(-))
Terraform Beta: Diff ( 1 file changed, 4 insertions(+), 3 deletions(-))
TF Validator: Diff ( 2 files changed, 3 insertions(+), 3 deletions(-))

[modular-magician]

Tests analytics

Total tests: 2058
Passed tests 1829
Skipped tests: 226
Failed tests: 3

Action taken

Triggering VCR tests in RECORDING mode for the tests that failed during VCR. Click here to see the failed tests

TestAccFirebaserulesRelease_BasicRelease|TestAccContainerCluster_withConfidentialNodes|TestAccContainerCluster_withAddons

[modular-magician]

Tests passed during RECORDING mode:
TestAccFirebaserulesRelease_BasicRelease[view]

Tests failed during RECORDING mode:
TestAccContainerCluster_withAddons[view]
TestAccContainerCluster_withConfidentialNodes[view]

Please fix these to complete your PR
View the build log or the debug log for each test