SDK / exoplayer

JaCoCo introduces private synthetic methods (even on interfaces) which
have to be skipped when checking that a 'forwarding' implementation does
forward everything. Instead we can use the existing `getPublicMethods()`
method which implicitly skips these (since they're private).

PiperOrigin-RevId: 533130932
(cherry picked from commit 1c104f66e182ce5f9d591375e3b683a3166749ce)