[rptest] Fix "ContainerAlreadyExists" in test_recovery_mode

[clee]

Occasionally, rptest/tests/recovery_mode_test.py::RecoveryModeTest.test_recovery_mode fails with an Azure storage "container already exists" error. If we try to create a container but it already exists, we should just treat that as a victory and move on instead of failing the test.

Further digging revealed that test_recovery_mode is actually calling RedpandaService.start() twice per test execution, and the second execution explains why the Azure storage bucket/container name "already existed" - it was created by the first call to RedpandaService.start()

Backports Required

• none - not a bug fix
• none - this is a backport
• none - issue does not exist in previous branches
• none - papercut/not impactful enough to backport
• v24.3.x
• v24.2.x
• v24.1.x

Release Notes

• none

[vbotbuildovich]

ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/59510#0193adb2-d31e-4493-912a-d3d639a0843d
ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/59557#0193b1e1-ff8a-4dcc-95f8-676d917fcf44
ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/59557#0193b1e5-a921-4426-afd1-bf0c187b1b89

[andrewhsu]

removing self from reviewer because PR already has suitable reviewers, but feel free to add me back if there is something specific needed to review

[vbotbuildovich]

non flaky failures in https://buildkite.com/redpanda/redpanda/builds/59557#0193b1e5-a925-4799-b623-6d40ec364726:

"rptest.tests.consumer_group_balancing_test.ConsumerGroupBalancingTest.test_coordinator_nodes_balance"

[vbotbuildovich]

Retry command for Build#59557

please wait until all jobs are finished before running the slash command

/ci-repeat 1
tests/rptest/tests/consumer_group_balancing_test.py::ConsumerGroupBalancingTest.test_coordinator_nodes_balance

[clee]

/ci-repeat 1
tests/rptest/tests/consumer_group_balancing_test.py::ConsumerGroupBalancingTest.test_coordinator_nodes_balance

[ivotron]

lgtm. Would be good to launch the test on cdt just to double check all works well there too

[clee]

/cdt
rptest/tests/recovery_mode_test.py::RecoveryModeTest.test_recovery_mode