Mock an action response to prevent the test case sending HTTP request

[crazytonyli]

Description

This test case has been pretty flaky. In case where it passed, it took more than 2 seconds to finish. It seems to me that this test case is making an actual HTTP request from saveAddress function. Other similar test cases in this test class use testingStores.whenReceivingAction as a way to stub HTTP response, this PR adds the same code to this test case.

Testing instructions

CI jobs passes, and test_loading_indicator_gets_disabled_after_the_network_operation_completes test case takes less than 1 seconds to finish.

Screenshots

N/A

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[crazytonyli]

"0.178 seconds" in the Unit Tests execution logs should've verified this PR's fix.

[06:33:44]: ▸ ✓ test_loading_indicator_gets_disabled_after_the_network_operation_completes (0.178 seconds)

[mokagio]

Brilliant!