[Contextual Edu] Add ignore tag until test is fixed

Ignore test until the test is fixed. Seems TemporaryFolder rule is not
able to create temp folder. Will look into it and fix it in another CL.

Bug: 384284415
Test: ContextualEducationRepositoryTest
Flag: com.android.systemui.keyboard_touchpad_contextual_education
Change-Id: Idc450a3f755207c6c950a9b24083a0aa47f6dc79