MediaControllerCompat: Fix the test failure of getRatingType()

A test for getRatingType() could fail when it's called before getting a
extra binder. Currently this is an intended behavior so this change
postpones the assertion until the result becomes available.

Bug: 34248838
Test: ./gradlew support-media-compat:connectedCheck on the API 21 device
Change-Id: I410d4e2437276d0146ab4725b9afff137e2c7e95
(cherry picked from commit bb1548192e230ad6cc1fbc0856837d58abf342c1)
1 file changed