Test: Fix chopsticks test Interlay -> Polkadot AssetHub

[bvotteler]

Recent changes to the AssetHub's logic broke chopsticks tests when sending USDC or USDT from Interlay to AssetHub.

The main change was that the USDC/T amounts are converted to DOT before sent as fees. That seems to make the tests fail even though the destination fee estimates are set high enough.

Find out which evaluation logic fails, fix it, and reenable the test cases.

For reference: the test case was disabled in commit 9b3fb50