Remove placeholder summary text in auto-rotate preference

- Remove the %s from xml and set it in code instead.
- This is hack to make search stop display %s. It's fixed properly in
  master but we don't want to cherry-pick the master change because of its
  size and risk.

Bug: 36101902
Test: rerun robotests
Change-Id: I0e03957532b265c15d5cc0754396aea26e5cd8a1
Merged-In: If42cceb74296814311eb0eff8e26b4a48a1c4d29