Revert "Refactoring DetailsBackgroundParallaxHelper."

ag/1459549 broke support library test builds:
https://android-build.googleplex.com/builds/submitted/3301972/support_test_apks/latest/logs

This reverts commit d7ba0d89531101088939239bb0339658dbe6c85b.

Change-Id: Ia60f9696e2bce6952e46763c645151f0b93a126e
15 files changed