skip the country code test when the country code is not support

Setting country code is not a must support feature on all platforms.
This commit skips the country code related tests when the platform
doesn't support setting the country code.

Bug: b/401793629
Test: atest ThreadNetworkIntegrationTests

Change-Id: I6bb8444f70afb2635d7791af2128741bc02e8ff3
3 files changed