test(0x): enable AdvancedMode for transformERC20 blind-sign

transformERC20 to the 0x Exchange Proxy is blind contract data; since 7.15.0
the device hard-rejects blind data unless AdvancedMode is on (Insight clear-
signing policy). Matches the existing test_sign_longdata_swap pattern in this
file. Fixes the lone python-integration-tests failure after the firmware
clear-signing merge.

Author: BitHighlander

tests/test_msg_ethereum_erc20_0x_signtx.py

@@ -166,6 +166,12 @@ def test__sign_transformERC20(self):
         self.requires_fullFeature()
         self.requires_firmware("7.1.5")
         self.setup_mnemonic_nopin_nopassphrase()
+        # transformERC20 to the 0x Exchange Proxy is blind contract data (no
+        # recognized token / contract handler). Since 7.15.0 the device
+        # hard-rejects blind contract data unless AdvancedMode is on (Insight
+        # clear-signing policy) — same as test_sign_longdata_swap above. This
+        # test checks signing correctness, so run it in expert mode.
+        self.client.apply_policy("AdvancedMode", 1)
 
         sig_v, sig_r, sig_s = self.client.ethereum_sign_tx(
             # Data from: