Fix MediaRoute2Info not having a name in a unit test.

MediaRoute2Info#getName() can't return null, but the mocks in the test didn't
provide any value for that field that led to an NPE.

Bug: 428663871
Flag: EXEMPT TEST_ONLY
Test: atest InfoMediaManagerTest
Change-Id: Ib96717c837941accea2c0fba91dd0941c57c154c