Clarify policy transparency test for work profile IME

Make the test instruction explicit that the work profile IME
settings should be checked instead of the primary profile settings.
Also change the "Open Settings" button target to open Settings
landing page instead of primary profile IME settings, which caused
confusions previously.

Change-Id: Ib960776e8774034a1206247b0ef75eb5621627c8
Fix: 136974051
Test: manually execute CtsVerifier.