[TF] Add default for GKE maintenance window

[sionescu]

Terraform will complain that the default is null.
The default maintenance window is Monday-Friday, between 7am and 11am Pacific time.

[github-actions]

✅ Forge suite compat success on testnet_2d8b1b57553d869190f61df1aaf7f31a8fc19a7b ==> 5226e0f021d011e60ff54afaffdccf7192078529

Compatibility test results for testnet_2d8b1b57553d869190f61df1aaf7f31a8fc19a7b ==> 5226e0f021d011e60ff54afaffdccf7192078529 (PR)
1. Check liveness of validators at old version: testnet_2d8b1b57553d869190f61df1aaf7f31a8fc19a7b
compatibility::simple-validator-upgrade::liveness-check : committed: 8758 txn/s, latency: 3746 ms, (p50: 3700 ms, p90: 5200 ms, p99: 6000 ms), latency samples: 297780
2. Upgrading first Validator to new version: 5226e0f021d011e60ff54afaffdccf7192078529
compatibility::simple-validator-upgrade::single-validator-upgrade : committed: 4505 txn/s, latency: 6906 ms, (p50: 7500 ms, p90: 8800 ms, p99: 9500 ms), latency samples: 171200
3. Upgrading rest of first batch to new version: 5226e0f021d011e60ff54afaffdccf7192078529
compatibility::simple-validator-upgrade::half-validator-upgrade : committed: 4128 txn/s, latency: 7519 ms, (p50: 8600 ms, p90: 10200 ms, p99: 10700 ms), latency samples: 156880
4. upgrading second batch to new version: 5226e0f021d011e60ff54afaffdccf7192078529
compatibility::simple-validator-upgrade::rest-validator-upgrade : committed: 7183 txn/s, latency: 4631 ms, (p50: 4700 ms, p90: 6600 ms, p99: 8100 ms), latency samples: 244240
5. check swarm health
Compatibility test for testnet_2d8b1b57553d869190f61df1aaf7f31a8fc19a7b ==> 5226e0f021d011e60ff54afaffdccf7192078529 passed
Test Ok

• Grafana dashboard
• Humio Logs
• Test runner output
• Test run is land-blocking

[github-actions]

✅ Forge suite land_blocking success on 5226e0f021d011e60ff54afaffdccf7192078529

performance benchmark : committed: 5503 txn/s, latency: 7214 ms, (p50: 5700 ms, p90: 9600 ms, p99: 28000 ms), latency samples: 2349860
Max round gap was 1 [limit 4] at version 353906. Max no progress secs was 3.860585 [limit 10] at version 2591836.
Test Ok

• Grafana dashboard
• Humio Logs
• Test runner output
• Test run is land-blocking

[github-actions]

✅ Forge suite framework_upgrade success on aptos-node-v1.3.0_3fc3d42b6cfe27460004f9a0326451bcda840a60 ==> 5226e0f021d011e60ff54afaffdccf7192078529

Compatibility test results for aptos-node-v1.3.0_3fc3d42b6cfe27460004f9a0326451bcda840a60 ==> 5226e0f021d011e60ff54afaffdccf7192078529 (PR)
Upgrade the nodes to version: 5226e0f021d011e60ff54afaffdccf7192078529
framework_upgrade::framework-upgrade::full-framework-upgrade : committed: 4773 txn/s, latency: 6903 ms, (p50: 7100 ms, p90: 9000 ms, p99: 10200 ms), latency samples: 171840
5. check swarm health
Compatibility test for aptos-node-v1.3.0_3fc3d42b6cfe27460004f9a0326451bcda840a60 ==> 5226e0f021d011e60ff54afaffdccf7192078529 passed
Test Ok

• Grafana dashboard
• Humio Logs
• Test runner output
• Test run is land-blocking