e2e: Avoid setting wrong routes for host-local IPAM

[zeeke]

The IPAM configuration:

{
"type":"host-local",
"subnet":"10.10.10.0{"type":"host-local",
"subnet":"10.10.10.0/24",
"rangeStart":"10.10.10.171",
"rangeEnd":"10.10.10.181",
"routes":[{"dst":"0.0.0.0/0"}],
"gateway":"10.10.10.1"
}

Can lead to the following pod ip route configuration:

default via 10.10.10.1 dev net1
default via 10.128.0.1 dev eth0
10.10.10.0/24 dev net1 proto kernel scope link src 10.10.10.172
10.128.0.0/23 dev eth0 proto kernel scope link src 10.128.0.135
10.128.0.0/14 via 10.128.0.1 dev eth0

which causes connectivity issues.

Avoid setting default routes to unknown gateways.

[github-actions]

Thanks for your PR,
To run vendors CIs, Maintainers can use one of:

• /test-all: To run all tests for all vendors.
• /test-e2e-all: To run all E2E tests for all vendors.
• /test-e2e-nvidia-all: To run all E2E tests for NVIDIA vendor.

To skip the vendors CIs, Maintainers can use one of:

• /skip-all: To skip all tests for all vendors.
• /skip-e2e-all: To skip all E2E tests for all vendors.
• /skip-e2e-nvidia-all: To skip all E2E tests for NVIDIA vendor.
  Best regards.

[coveralls]

Pull Request Test Coverage Report for Build 12176930359

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 29 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.09%) to 47.08%

---

Files with Coverage Reduction	New Missed Lines	%
controllers/generic_network_controller.go	5	74.38%
controllers/helper.go	24	60.67%

Totals
Change from base Build 12046950769:	-0.09%
Covered Lines:	7176
Relevant Lines:	15242

---

💛 - Coveralls

[ykulazhenkov]

LGTM, thanks for fixing this